GOP Sen. Josh Hawley announced on Tuesday that he plans to object to swift consideration of President-elect Joe Biden’s nominee to lead the Department of Homeland Security, a move that will delay the installment of Biden’s national-security team.

Hawley, who has come under heavy scrutiny for leading a push to object to the Electoral College certification of Biden’s victory, cited the incoming administration’s immigration policies. The Missouri senator argued that the nominee, Alejandro Mayorkas, “has not adequately explained how he will enforce federal law and secure the southern border given President-elect Biden’s promise to roll back major enforcement and security measures.”

Senate Democrats had been pushing for quick floor votes on Biden’s national-security nominees in light of the insurrection at the Capitol earlier this month. Mayorkas is still likely to be confirmed by the full Senate, but Hawley’s move effectively delays a floor vote.

Sean Savett, a spokesman for the Biden transition, said the nation “urgently needs” a Senate-confirmed DHS secretary on day one of Biden’s presidency given the extensive and complicated national-security challenges of late.

“Senator Hawley's threat to disrupt historical practice and try to leave this vital position vacant is dangerous, especially in this time of overlapping crises when there is not a moment to waste,” Savett added.

Appearing before the Senate Homeland Security Committee for his confirmation hearing Tuesday, Mayorkas vowed to do everything in his power to prevent attacks like the one that targeted the Capitol — an insurrection based on unsubstantiated claims that the 2020 presidential election was “stolen” from President Donald Trump.

Mayorkas addressed the recent insurrection head-on, less than two weeks after a pro-Trump mob stormed the Capitol in a series of riots that left five people dead and resulted in the president’s second impeachment. It was the dominant theme in the 2 1/2 hour hearing that also touched on immigration policies and corruption allegations.

“If I should have the honor of being confirmed, I will do everything I can to ensure that the tragic loss of life, the assault on law enforcement, the desecration of the building that stands as one of the three pillars of our democracy, and the terror felt by you, your colleagues, staff, and everyone present, will not happen again,” Mayorkas, 61, told senators.

Mayorkas’ confirmation hearing comes as Washington is locking down ahead of Biden’s inauguration on Wednesday, with fences blocking off large swaths of the city and 25,000 National Guard troops patrolling the streets.

Senate Democrats had been pushing to confirm Mayorkas to lead DHS as soon as this week, noting that the recent national security challenges in the nation’s capital demand steady leadership atop a department that has seen unprecedented turnover at the leadership level during Trump’s administration.

Democrats, who are set to step into the Senate majority later this week, will soon have the power to set the Senate’s schedule, but any one senator can object to swift consideration of a nominee, which allowed Hawley to pump the brakes on the entire process.

While Mayorkas will likely have enough votes to secure confirmation on the Senate floor, he was pressed during the hearing Tuesday about a 2015 inspector general report charging that he displayed “an appearance of favoritism and special access” for certain visa recipients. The report alleged serious abuses with the EB-5 visa process in particular, accusing Mayorkas of giving preferential treatment to political allies.

While Republicans were not adversarial with Mayorkas, they focused intently on the IG report. Ohio Sen. Rob Portman, the top Republican on the Homeland Security Committee, said the report was “concerning” and detailed the claims in his opening statement. Portman added that he recently spoke with John Roth, the DHS inspector general at the time, who told him that he stands by the 2015 report.

“There is a troubling inspector general [report] with regard to his previous job,” Portman told reporters after the hearing, though he acknowledged that Mayorkas has “a lot of experience” in the national security field.

Mayorkas has pushed back against the favoritism allegations, which first surfaced in a 2012 whistleblower complaint, calling them false and unfounded. A Biden transition official said Mayorkas inherited a “badly broken” visa system and “took a series of steps to proactively reform the EB-5 program and strengthen the quality and integrity of the process.”

Sen. Chuck Grassley (R-Iowa) suggested he might even delay quick confirmation of Mayorkas over the controversy, with which he has been intensely involved since the initial whistleblower complaint was filed. Democrats are hoping to confirm Mayorkas as soon as Wednesday, hailing Mayorkas as an experienced and steady leader of a department that has been under siege.

Biden will enter office with zero Cabinet confirmations, which is highly unusual for an incoming president. The Senate usually processes high-level national-security nominations in early January as a show of deference toward the new president.

Mayorkas’ hearing came on the final full day of Trump’s presidency, when the outgoing commander-in-chief has been avoiding the spotlight and hunkering down in the White House ahead of his departure on Wednesday morning. Trump was barely mentioned during the hearing, but GOP senators pressed Mayorkas on preserving at least some of Trump’s DHS policies, particularly with regard to immigration.

Mayorkas acknowledged the “horrifying” nature of the Jan. 6 attack and noted that there remains much to be learned about the full extent of the violent attack. He drew on his experience as an immigrant fleeing a communist country as he seeks to lead a department of more than a quarter-million employees.

Mayorkas, who was born in Cuba and grew up in Miami and Los Angeles, has an extensive resumé of government service. He served as U.S. Attorney for the Central District of California from 1998 to 2001, and led U.S. Citizenship and Immigration Services for the first four years of Barack Obama’s administration. He later served as deputy Homeland security secretary from 2013 to 2016.

“The love for this country that I learned from my parents made the Jan. 6 attack on the Capitol all the more horrifying,” Mayorkas told senators.

In addition to Mayorkas, Biden’s nominees to lead the Treasury Department, State Department, Pentagon, and the Office of the Director of National Intelligence also appeared for confirmation hearings on Tuesday as Biden pushes for swift approval of his picks, specifically those involving U.S. national security. That could prove to be difficult for Biden, though, as the Senate is set to soon put Trump on trial again after the House impeached him last week for inciting the riots at the Capitol.

Biden’s administration is expected to depart significantly from the Trump administration’s DHS policies, most notably on immigration and border security. Biden has vowed to hold accountable the officials responsible for the so-called “zero tolerance” policy at the southern border, which resulted in migrant children being separated from their parents and housed in cages. The policy was pushed by Trump and his first attorney general, Jeff Sessions, in particular.

Biden is expected to unveil a sweeping new immigration plan when he takes office, and he has pledged more broadly to rollback the Trump administration’s hardline immigration policies. Last week, a new wave of migrants began a trip toward the U.S. southern border from Central America, heightening security concerns.

As director of U.S. Citizenship and Immigration Services, Mayorkas was critical in implementing the Deferred Action for Childhood Arrivals program, which provides a legal shield to undocumented immigrants who were brought to the U.S. by their parents. Trump has repeatedly sought to scrap the program, and Biden is seeking to codify it into law.

Biden is also aiming for stability with his Cabinet after four years of firings and resignations that led to several departments and agencies not having a Senate-confirmed leader. The Department of Homeland Security, for example, had six secretaries throughout Trump’s four years, and only two of them were confirmed by the Senate.

In the shadow of Joe Biden’s inauguration as the 46th president of the United States, the Senate is set to put his predecessor on trial for high crimes and misdemeanors — potentially barring him from holding federal office ever again.

The House impeached President Donald Trump last week for “willful incitement of insurrection,” a grave charge that stems from the president’s encouragement of rioters who on Jan. 6 stormed the Capitol based on the false notion that the 2020 presidential election was “stolen.” The insurrection left five people dead and countless others injured.

The trial’s exact start date isn’t yet certain. Speaker Nancy Pelosi has not formally transmitted the impeachment article to the Senate — a move that, according to the Senate’s rules, triggers the start of the trial on the very next day. Pelosi’s deputies have said she will send the article across the Capitol “soon” but have not given a specific timeline.

Here’s everything you’ll need to know once the trial gets underway.

Can the Senate hold a trial for an ex-president?

It’s the debate that has been raging in legal and constitutional circles for a week: Does the Senate have any business deploying its most potent punishment against Trump as a private citizen?

One camp, personified by Sen. Tom Cotton (R-Ark.), says no: “The Founders designed the impeachment process as a way to remove officeholders from public office — not an inquest against private citizens.” In other words, you can’t remove from office someone who has already relinquished the office.

The other view, given voice in a recent op-ed by Steve Vladeck, a University of Texas law professor, says that of course a former president can be convicted. The Constitution doesn’t just provide for removal but also for the Senate to bar that former president from ever holding federal office again. In Vladeck’s view, how could the framers have designed a “disqualification” system that could be defeated if the target simply resigned minutes before the process was complete?

The bottom line is this: Congress, by deciding to hold an impeachment trial after Trump’s exit, is daring the courts to wade into territory that judges typically avoid. The Constitution gives the House and Senate the “sole power” to handle matters of impeachment. Judges have frequently cited this to determine that they have no role in telling lawmakers how to wield their own constitutional power. It’s safe to think they’ll end up there again.

Will the 2021 trial work differently than last year’s?

A year ago, Congress spent the first full day of Trump’s impeachment trial in a fierce battle over the rules, which dictate the entire course of the trial. Back then, conviction was a nonstarter — most Republican senators had pretty much ruled it out from the start, and the major questions were how uncomfortable Democrats could make them before they summarily let Trump off the hook.

This time, with a slew of undecided senators — including Mitch McConnell of Kentucky, the outgoing majority leader — the rules loom even larger.

One thing to watch for: Do Republicans like Sen. Lindsey Graham (R-S.C.), who oppose the trial, try to force a vote on dismissing the charges? If they do, it will probably fail since the Senate will be split 50-50 along party lines, and enough Republicans have signaled openness to conviction that they’re unlikely to end the trial before it begins. But that vote could also be an early test for just how many Republicans might be open to conviction.

After sweeping aside any dismissal attempt, the Senate must determine how much time to give each side to lay out its arguments. In 2020, it was 24 hours apiece. Seven House impeachment prosecutors and a team of veteran White House and constitutional lawyers spent six days offering their cases. This time, Pelosi has selected nine impeachment managers and Trump hasn’t even identified a legal team to deliver his case.

Rep. Jamie Raskin (D-Md.), the lead impeachment manager, has not tipped his hand on specific strategies, but he has offered this broad exhortation: “We just want the Senate to conduct a serious trial where every member of the Senate lives up to his or her constitutional oath to render impartial judgment as a juror.”

One unusual aspect of this trial? Every impeachment manager and every juror was also a victim of the alleged crime: incitement of insurrection. The same people trying and deciding the case were the ones ducking behind chairs and dodging violent mobs less than two weeks ago, while they frantically pleaded with Trump for help that only belatedly arrived.

Raskin intends to lean on that experience as he tells a big-picture story about the insurrection as an “attack on our country.”

“There are thousands of people that work on Capitol Hill, not just members but staff members, and Capitol Hill police officers, who were pushed and shoved and punched in the face, pummeled and hit over the head with fire extinguishers,” Raskin said Sunday on CNN’s “State of the Union.” “And the president did nothing to stop it for more than two hours as members of Congress called him and begged him to do something and he continued to watch it on TV and enjoy their insurrection tailgate party.”

Democrats will also point early and often to the arguments lodged by the 10 Republicans in the House who voted to impeach Trump, including Rep. Liz Cheney of Wyoming, the No. 3 House Republican.

Last time, Democrats also sought to empower Chief Justice John Roberts — required by the Constitution to preside over presidential impeachment trials — to decide matters of executive privilege. But Republicans rejected the suggestion, and Roberts himself signaled he intended to play a low-key role.

How likely is a conviction?

Make no mistake about it: The House impeachment managers face an uphill climb as they try to persuade enough senators to vote in favor of conviction. Last year, there was virtually no chance that the Senate would reach the two-thirds threshold required, but this year, it seems at least possible that at least 17 Republicans could join all 50 Democrats to vote to convict.

For starters, McConnell has adopted a markedly different posture. Ahead of the last trial, McConnell said there was “no chance” Trump would be booted from office and was a key defender of the president. But this time around, McConnell is keeping an open mind and is urging his fellow GOP senators to keep their powder dry. It could mean that Sen. Mitt Romney of Utah, the only Republican who voted to convict Trump in the first impeachment trial, will have company this time around.

Trump’s exit from the White House alone isn’t likely to be a good enough reason for Republicans to feel comfortable with voting to convict him. Even though the president will be out of office by the time the Senate votes on conviction, he will remain a force within the GOP for years to come, and he has pledged to remain involved in campaigns. A chief concern for Republicans facing reelection in 2022 and 2024 is that Trump could back a primary challenger.

Still, convicting Trump and barring him from holding federal office could clear a pathway for the countless Republicans considering seeking the GOP presidential nomination in 2024, many of whom serve in the Senate. If Trump decided to run for president again in 2024, he could be the favorite to secure the party’s nomination.

McConnell will be the most important person to watch in determining whether the Senate has the votes to convict Trump. If he votes “yes,” it’s easy to see at least 16 other Republicans joining him. If he doesn’t, conviction becomes much less likely.

Will the House managers attempt to call witnesses?

At last year’s trial, Democrats were pressing vigorously for the Senate to hear testimony from additional witnesses who could shine light on Trump’s alleged misconduct. But this year, it might not be in Democrats’ interest to push for witnesses.

Democrats have raised concerns about holding a trial in the opening days of Biden’s presidency because it would delay Senate action on staffing his Cabinet and considering additional Covid-19 relief legislation.

At the same time, with so many Republicans appearing open to conviction this time around, it might be beneficial for the House impeachment managers to be able to call witnesses, especially because the House did not conduct a formal impeachment inquiry before last week’s vote.

For now, the House impeachment managers are remaining mum about their strategy when it comes to witnesses. Democrats have maintained that a full investigation is not necessary because the evidence for impeachment is in the public domain — and lawmakers themselves were witnesses to an insurrection that put their lives in danger.

“The last [impeachment trial] was information brought to us by others,” said Sen. Debbie Stabenow of Michigan, the No. 4 Senate Democrat, in an interview. “This is an impeachment based on what we experienced, and what the president of the United States said, in speeches, that day, that were videotaped. All the evidence is really right in front of us.”

Indeed, senators themselves were forced to hastily evacuate the Senate chamber and were just feet away from the violent mob that eventually made its way onto the Senate floor. During last year’s trial, the House managers used several audio and video clips to aid their legal arguments; this year they’re likely to use to their advantage the hours of troubling footage showing the rioters desecrating the Capitol, violently beating police officers and rummaging through the Senate chamber — in addition to clips of Trump’s remarks ahead of the storming of the Capitol.

One potential witness on Democrats’ list is Brad Raffensperger, the Georgia secretary of state. Trump has mercilessly harangued Raffensperger and Gov. Brian Kemp, who are both Republicans, for not adopting his unsubstantiated claims of voter fraud in the state. Earlier this month, the president held an hourlong phone call with Raffensperger during which Trump pressured the secretary of state to “find” votes on his behalf to overturn Biden’s victory in Georgia.

Prosecutors in Atlanta are reportedly considering opening a criminal investigation into Trump over his pressure campaign.

Still, Democrats might reject outside witnesses in the name of completing the trial more quickly.

“We have so much to do,” Stabenow added. “There's no reason to spend time that isn’t necessary. We need to follow the law and the Constitution, treat this with seriousness. And the process needs to have integrity. At the same time, we need to have it move along in a way that will allow it to be completed so that we can continue the other critical things that have to get done for the country.”

Disarray on the president’s legal team

In previous years, a chance to represent presidents would be a lawyer’s dream, a crowning career achievement that could also mean lucrative professional opportunities in the future. But Trump has proven to be a difficult client and, in this case, a toxic one. Few appear to be lining up to eagerly combat charges that the president — through a monthslong campaign of false and pernicious claims of election fraud — motivated the frothing Jan. 6 mob to attack the Capitol and hunt down Pelosi and Vice President Mike Pence.

In 2020, Trump recruited former independent counsel Ken Starr and Harvard law professor Alan Dershowitz to mount big-picture legal arguments, which were effective with some open-minded senators. He also had veteran White House lawyers Pat Cipollone and Patrick Philbin at the defense table, along with outside counsels Jane and Marty Raskin, former Florida Attorney General Pam Bondi and conservative lawyer Jay Sekulow.

This time, none of the same attorneys appear poised to return. Dershowitz has indicated he generally supports the view that Trump’s Jan. 6 remarks to the rally crowd, which later became the violent mob, are protected free speech. But he has indicated he will probably make those arguments from the sidelines this time.

That has left Trump’s personal lawyer Rudy Giuliani — whose own efforts to aid Trump’s campaign to overturn the election have drawn bipartisan scorn on Capitol Hill — as one of the only prominent figures standing in Trump’s legal defense orbit. But reports suggest that Giuliani has also been ruled out. Over the weekend, Trump campaign spokesman Hogan Gidley said Trump had simply not decided on an impeachment legal team yet.

Burgess Everett contributed to this report.

An impeachment trial is looming, and the Senate majority is set to change hands in the next couple days. But when the dust settles after Joe Biden’s inauguration as president, Democrats are hoping he won’t have a totally bare Cabinet.

Senior Democrats are optimistic that Biden will see at least two of his top national security officials confirmed either on Inauguration Day or shortly thereafter, particularly after the pro-Trump siege of the Capitol last week by rioters and extremists. That would allow Biden to at least claim equal treatment to President Donald Trump, who had his Homeland Security and Defense secretaries confirmed on Inauguration Day, followed days later by his CIA director.

Democrats also hope to make Janet Yellen the new Treasury secretary and Tony Blinken the new secretary of State in the coming days. But they say the minimum bar should be confirming Alejandro Mayorkas to the Department of Homeland Security and retired Gen. Lloyd Austin to the Defense Department to beef up national security.

“Obviously we need a Department of the Treasury and other key positions, certainly. But in terms of the security of the country, there’s a great sense of urgency,” said Sen. Debbie Stabenow (D-Mich.), the No. 4 Democratic leader, in an interview on Monday afternoon. Republicans “should absolutely be working with us to do at minimum, the confirmations that we supported for President Trump.”

Mayorkas, Austin, Blinken, Yellen and Director of National Intelligence nominee Avril Haines all have hearings on Tuesday. Haines is another prospect for quick confirmation given the politics and mood in Congress about the security breach in the Capitol.

“I would hope that our Republican colleagues would join us in putting the secretary of Defense, secretary of Homeland Security, secretary of State, attorney general and others in office ASAP,” Senate Democratic Leader Chuck Schumer said on Sunday. “When President Trump was president on the first day, both Defense and Homeland Security were put into office. We Democrats supported that happening, we need cooperation.”

In the Senate, any one senator can object to quick votes. When Schumer becomes majority leader, he can force votes himself on Cabinet nominees, but each would take several days. Democrats can confirm nominees in the Senate unilaterally once they have the majority.

While Austin is popular in both parties, his confirmation is more difficult because he needs a waiver to serve as Defense secretary since he has not been out of the military for the minimum of seven years. The House must pass that waiver before he can be confirmed, and Democratic leaders there say it’s a top priority.

“The internal security threat the U.S. faces right now is serious. We need a Secretary of Defense on the job immediately,” tweeted Sen. Chris Murphy (D-Conn.), who explained he voted against Mattis’ waiver but supports Austin’s because there’s “simply much less reason to be fearful of a recently retired general running DoD under Biden.”

Confirmation of any Cabinet officials could be tough on Inauguration Day for a variety of factors. Three new Democratic senators, Jon Ossoff and Raphael Warnock of Georgia plus Alex Padilla of California, must be sworn in. And Kamala Harris must be the vice president to give Democrats a 50-seat majority with Harris breaking ties. All those events should be official by late Wednesday or Thursday.

Moreover, the committees and the overall Senate must be organized by Schumer and Senate Republican Leader Mitch McConnell. Those negotiations are ongoing, though they will likely follow much of the precedent from the last 50-50 majority 20 years ago. And heightening the intrigue: Speaker Nancy Pelosi has yet to send Trump’s impeachment articles over to the Senate.

An impeachment trial could preempt other business unless McConnell and Schumer strike an agreement on a schedule for Biden’s confirmations and the trial. Sen. Ben Cardin (D-Md.) said on MSNBC on Monday that he believed the impeachment trial would not start on Inauguration Day.

McConnell and Schumer have been in discussions for several days and remain in contact, said a source familiar with the matter. McConnell has said he would treat Biden's nominees much better than Schumer treated Trump’s, though Democrats remember McConnell not being especially kind to President Barack Obama's picks.

“So much of how we proceed is about whether or not Mitch McConnell is gonna want to help get the personnel in place for the security of the country and want to work with Chuck Schumer to move forward. Or will he take a position he has before with President Obama?" Stabenow said. “We don't know. And that makes a difference.”

Andrew Desiderio contributed to this report.