PIERRE, S.D. (AP) - South Dakota House lawmakers on Tuesday began impeachment proceedings against the state’s attorney general, who is facing misdemeanor charges for striking and killing a man with his car.

Republican lawmakers introduced a resolution in the House to impeach the state’s top law enforcement officer, Jason Ravnsborg, ...

The officials in charge of securing the Capitol on Jan. 6 say a tangled mess of conflicting orders and unanswered calls culminated in an hourslong delay by the Pentagon in deploying National Guard troops to quell the insurrection that threatened the presidential transfer of power.

In Tuesday testimony to two Senate committees, former Capitol Police Chief Steven Sund said the Pentagon dragged its feet for hours on Jan. 6 — even after law enforcement officials pleaded for backup. Already, a mob inspired by then-President Donald Trump had planted two explosives nearby, breached the Capitol and battered police officers with clubs, mace and other weapons.

Sund and acting D.C. police chief Robert Contee described to senators a conference call that afternoon with senior security personnel during which a top Pentagon official, Lt. Gen. Walter Piatt, said he would recommend against deploying the National Guard for fear of the “optics” of armed troops in front of the Capitol. Sund and Contee said they informed Piatt that their officers, already beleaguered and beaten by the mob, were desperate for help.

“Lt. Gen. Piatt then indicated that he was going to run the request up the chain of command at the Pentagon,” recalled Sund who resigned after the riots. "Almost two hours later, we had still not received authorization from the Pentagon to activate the National Guard.”

Contee told lawmakers that he was “literally stunned” by Army officials’ nonchalant responses.

“Chief Sund was pleading for the deployment of the National Guard and in response to that, there was not an immediate ‘Yes, the National Guard is responding,’” Contee said.

That pivotal meeting about protecting the Capitol is likely to spark further questions by senators who were forced to flee for their lives during the insurrection. The rare joint oversight hearing on Tuesday was lawmakers’ first chance to expose the security failures that allowed rioters to overtake the Capitol last month. But Sen. Gary Peters (D-Mich.), chair of the Senate Homeland Security Committee, said that hearings would continue.

Sund used his testimony to defend his former force’s handling of Jan. 6, describing that day's collapse of the Capitol defenses as "not the result of poor planning or failure to contain a demonstration gone wrong."

"No single civilian law enforcement agency — and certainly not the USCP — is trained and equipped to repel, without significant military or other law enforcement assistance, an insurrection of thousands of armed, violent, and coordinated individuals focused on breaching a building at all costs," he told senators.

According to Contee, “available intelligence pointed to a large presence of” some extremist groups that had stirred violence at protests in the nation’s capital late last year. However, Contee said, D.C. “did not have intelligence pointing to a coordinated assault on the Capitol.”

In addition to Sund and Contee, the Senate heard from the former House and Senate sergeants-at-arms. But key details of their stories conflict.

For example, Sund claims he called then-House Sergeant-at-Arms Paul Irving early on in the assault — at 1:09 p.m. to request more help. But Irving says he has no memory of that call and was on the House floor at that time. He told lawmakers he didn’t get a formal request from Sund until after 2 p.m.

Lawmakers pressed Sund and Irving on that discrepancy and asked them to share phone records.

Sund also told senators that the Capitol Police’s intelligence unit received a report from the FBI on the evening before the insurrection that warned of extremist groups preparing for “war.” But Sund said that report never made it up the chain to him.

Irving and Michael Stenger, the then-Senate sergeant-at-arms, said they also never saw it.

Although the story of Jan. 6 has become clearer as hundreds of rioters have faced charges, high-level decision-making by top congressional security officials has so far remained shrouded in secrecy. That lack of transparency has clouded congressional efforts to ensure the Hill learns from the insurrection chaos.

“When you ask questions and you get an answer, it usually leads to even more questions,” Peters said, adding that he personally has “a long list of questions” for the former officials.

Sen. Amy Klobuchar (D-Minn.), chair of the Rules committee, said Tuesday that Pentagon officials would be testifying on the Hill next week about their roles in the response to the insurrection.

All of the security officials said in their Tuesday testimony that the intelligence about the protests that day — billed by Trump as a “wild” effort to “stop the steal,” part of a months-long campaign to cast doubt on Joe Biden’s Electoral College victory — pointed to a degree of lawlessness but not a concerted assault on the Capitol.

Had other security officials concluded that military backup could be necessary on Jan. 6, “I would not have hesitated to ensure the National Guard’s presence or to make any other changes necessary,” said Irving.

Another area that lawmakers are likely to tackle Tuesday at the joint hearing of the Homeland Security and Rules panels is the cause of Capitol Police officer Brian Sicknick’s death. Initial reports that Sicknick was struck and killed by a fire extinguisher have yet to be verified, but his death rocked the Capitol community and has become emblematic of the devastation that the rioters could have exacted had the day taken an even darker turn.

A third unknown hovering over the discussion is the roles Speaker Nancy Pelosi and then-Senate Majority Leader Mitch McConnell had in orchestrating the security response. Some details have begun to spill out, suggesting both leaders were perplexed by the failure of their chambers' sergeants-at-arms to immediately seek National Guard help — as well as the failure to have Guardsmen at the ready in advance — once the riot became a clear threat to lawmakers’ safety.

Leadership staff in both parties agreed during the crisis that Capitol Police leaders “should have asked for the National Guard's physical deployment to protect the U.S. Capitol complex well in advance of January 6th," said Drew Hammill, a Pelosi aide.

Sen. Roy Blunt of Missouri, the top Republican on the Rules Committee, said he wants to better understand the nature of the conversations between Stenger, Irving and Sund. Blunt also said he wants to examine whether the Capitol Police’s current structure “really works” — not just on a daily basis, but during emergency situations.

Later this week, the House Appropriations Committee will hear testimony from Sund’s successor, acting Capitol Police Chief Yogananda Pittman, as well as Irving’s successor, acting sergeant-at-arms Timothy Blodgett.

Tuesday’s hearing comes amid a nationwide push by law enforcement officials at all levels to track down and prosecute the worst actors of the Jan. 6 insurrection.

More than 200 participants in the riots have been arrested — some for simply trespassing, others for assaulting police. Still, prosecutions are likely to intensify. Biden’s attorney general nominee Merrick Garland told lawmakers Monday that he intends to make the investigation a top priority in the early days of his tenure.

Sund may also be pressed on outstanding investigations into three dozen Capitol Police officers, part of a force of about 2,000, whose actions during the protests raised questions. Six of them remain suspended during these reviews, the Capitol Police have confirmed. Lawmakers have also asked questions about whether any of their colleagues led unauthorized tours earlier that week for people who may have participated in the Jan. 6 attacks.

The House impeached Trump last month, but he was acquitted in the Senate. Trump has signaled he intends to remain a political force within the GOP, adding another layer of volatility to the ongoing investigations.

During the trial, the House’s impeachment managers emphasized that Trump publicly did little to quell the riots after they had begun and actually may have inflamed the situation further with tweets that seemed to celebrate the rioters’ actions as they stormed the building in his name. Trump’s lawyers argued that the White House was engaged in delivering help to the Capitol early, but that it got tangled in a web of multi-agency bureaucracy. They presented no details to support that claim.

That dimension will weigh on lawmakers as they consider whether to authorize the creation of an intensive review of all of the causes and policy gaps exposed by the Jan. 6 insurrection.

Democratic leaders have called for an investigative panel, modeled on the 9/11 Commission that probed the 2001 terror attacks, to examine disparate threads that contributed to the assault, and many Republicans have signaled openness to that push. But the contours of that commission has already provoked disagreement between the parties.

Sen. Rick Scott challenged the certification of Donald Trump's reelection loss, bashed Trump's second impeachment trial and recently spoke with the former president about Senate races. But don’t take that as the Florida Republican siding with Trump over Mitch McConnell.

In fact, the National Republican Senatorial Committee chair said he “absolutely” supports McConnell as Senate Republican leader. He gave no oxygen to Trump's trashing of McConnell as someone who “doesn’t have what it takes” following the GOP leader’s withering criticism of Trump’s lack of leadership during the Jan. 6 Capitol riot.

“I’m not going to get involved in that. My job as chair of the NRSC is just to focus on recruiting candidates and raising money,” Scott said on Monday afternoon. He said he told Trump he wants to win Senate races next year.

The crumbled alliance between Trump and McConnell, who worked hand-in-glove on political and legislative strategy for four years, has finally brought the GOP to the reckoning that never happened after the 2016 election. Trump may take another swipe at McConnell in the coming days at the Conservative Political Action Conference. But McConnell probably won’t hear it: He is not expected to speak at CPAC, according to Republican sources. McConnell still hasn’t spoken to Trump in more than two months.

And interviews with nearly a dozen Senate Republicans on Monday night make clear that it will take more than a war of words with Trump to knock McConnell off his perch. Both Sens. John Thune (R-S.D.) and John Cornyn (R-Texas), the two most likely successors to McConnell at the moment, back him vocally.

“Sen. McConnell’s been the best Republican leader since I’ve been here. He understands this place better than anybody,” Cornyn said. “I believe he enjoys the overwhelming support of the conference.”

Asked if he agreed with McConnell’s criticisms of Trump, Cornyn said: “I’m looking forward to the day we can move on to other things.” He said he had no plans to visit Trump in Florida, like Sen. Lindsey Graham (R-S.C.) and House Minority Leader Kevin McCarthy (R-Calif.) have done in recent days.

Many senators have little interest in refereeing McConnell’s seething comments about Trump’s “dereliction of duty” during last month's insurrection and Trump’s brutal assessment of McConnell’s “lack of political insight, wisdom, skill, and personality.” But few share the assessment by Sens. Ron Johnson (R-Wis.) and Graham that McConnell’s criticism of Trump has become a political anchor weighing on the GOP.

“Republicans have a big tent,” said Sen. Deb Fischer (R-Neb.). “There’s strength in having robust discussions. There’s strength in having differences of opinion. And politicians are always going to have back-and-forth."

“I support [McConnell]. I support the outsider part of the party as well,” said Sen. Mike Braun (R-Ind.). “The biggest disaster would be if we split in some fashion. It’s exactly what the Democrats would be looking for. And most of us are going to let time be our friend.”

For all the fanfare that the Trump-McConnell battle has received over the past two weeks, the ultimate referendum on who will guide the party won’t come for at least a year, until GOP Senate primaries begin unfolding in earnest. And McConnell’s willingness to wade into GOP primaries this cycle against Trump-backed candidates he sees as unelectable presages brutal internecine battles over control of the Senate on the Republican side.

In his two-page statement bashing McConnell, Trump said that “our America First agenda is a winner, not McConnell’s Beltway First agenda.” In an interview this month, McConnell said that the litmus test in primaries is simple: Who can win general elections?

“The issue is not whether you do or don't like Donald Trump, the issue is: Can you win in November?” McConnell said.

Since McConnell was just reelected unanimously as GOP leader in November, he won’t face a leadership campaign until after the next election. He’s won previous leadership races with no dissent, despite occasional grumbling from senators like Johnson, who was essentially abandoned by the national party in his 2016 reelection race.

If McConnell is as toxic among Republican voters as Trump's loyalists claim, it would be most obvious in deep-red states. But two GOP senators up for reelection in conservative states, James Lankford of Oklahoma and Mike Crapo of Idaho, both said they still support McConnell as GOP leader on Monday.

“People are going to have differences of opinion on different things at different times. That’s just drama,” Lankford said. “A year ago everybody was saying what a great tactician Mitch was.”

The Senate is not like the House; it’s less factionalized and there’s no organized opposition within the Senate GOP to McConnell as leader. Johnson said McConnell’s leadership position is “not even a question on the table.”

“When the leader speaks -- sure he can speak for himself -- but he also has to realize that what he says is going to reflect on the conference,” Johnson said. "I didn't appreciate what he said."

“I’m not aware of any leadership challenge to him. I don’t know of any,” said Sen. Josh Hawley (R-Mo.), who did not directly say he supports McConnell and suggested GOP voters have chosen the party’s direction already. “For voters, there is no civil war. They’ve made their choices. They don’t want to go back to an early time in the party."

McConnell just won re-election to a six-year term. And if he can hang on for two more years, he can match former Sen. Mike Mansfield (D-Mont.) as the longest-serving Senate party leader of all time.

But even more important is whether McConnell will edge out Chuck Schumer as majority leader and be able to put back some constraints on Biden’s presidency. It looked like McConnell had the majority secured before Georgia’s special elections, and it’s clear he didn’t exactly appreciate Trump’s repeated attacks on the electoral process and false claims of mass voter fraud that dominated that race.

“One of my favorite sayings about politics is, winners make policy and losers go home. The reason we may well pass a $1.9 trillion [coronavirus bill] … is because we lost the Senate,” McConnell said in the interview this month. “And the reason we lost, as everyone knows, is there was so much confusion down there about whether even voting made a difference that it undercut us.”

Marianne LeVine contributed to this report.