Donald Trump is moving fast in the wake of his impeachment trial to use the government to punish his enemies and pursue his political ends, underlining how his acquittal has helped make him one of history's most powerful modern Presidents.

• Trump defends firing key impeachment witness • Cuomo's warning: This is just the beginning

Sen. Susan Collins on Friday again defended her votes to acquit President Donald Trump in his Senate impeachment trial and said she opposes "any kind of retribution" against those who provided evidence against him -- the same day Trump fired two key witnesses in the inquiry.

President Donald Trump on Saturday defended the firing of Lt. Col. Alexander Vindman from the National Security Council.

A White House decision to remove two top officials who played key roles as witnesses in the Ukraine scandal prompted confusion in Washington and Kiev on Friday over the future of US foreign policy toward the embattled US ally at the heart of President Donald Trump's impeachment.

Freed from the yoke of impeachment, President Donald Trump did what he does best on Friday night: Exacted revenge on his enemies.

Supreme Court Justice Ruth Bader Ginsburg pointed on Friday to the US Senate, fresh off a near party-line acquittal vote to conclude the impeachment trial this week, as an example of the dangers of partisan polarization.

President Donald Trump fired key impeachment witness Gordon Sondland on Friday, along with Lt. Col. Alex Vindman.

House Democrats are sounding alarms that a prolonged fight for their party's presidential nomination will only serve to bolster President Donald Trump's reelection prospects, as many in their party grow anxious in the aftermath of his impeachment trial.

Lt. Col. Alex Vindman, the top Ukraine expert at the National Security Council, was pushed out of his role Friday months earlier than expected, according to a statement from his attorney. Vindman was not slated to leave until July, but had been telling colleagues in recent weeks he would likely leave soon. It was not his decision to leave, however, according to one person familiar with the situation.