Republican Susan Collins, key swing-vote senator, announces she will vote to acquit Trump

Maine Republican Sen. Susan Collins, a key swing vote in President Trump's impeachment trial, announced Tuesday she would vote to acquit on both articles of impeachment -- noting that Democrats' "abuse of power" charge "did not even attempt" to allege that Trump had committed a crime, and instead constituted a "difficult-to-define, non-criminal act."

Even as she criticized Trump's behavior as "flawed," Collins further slammed House Democrats for delaying transmitting the articles of impeachment to the Senate for more than a month, saying the stalling and posturing undercut their arguments that the president was an imminent threat.

Last week, along with Utah GOP Sen. Mitt Romney, Collins had broken ranks with her fellow Republicans to vote in favor of additional witnesses in the Senate trial. Trump, who is now set to be overwhelmingly acquitted by the Senate on Wednesday, will deliver the annual State of the Union address before Congress Tuesday night amid record-high approval ratings.

Collins began her remarks on the Senate floor by observing the increasingly partisan nature of the impeachment process.

"For more than 200 years after our Constitution was adopted, only one president faced an impeachment trial before the United States Senate -- that was Andrew Johnson in 1868," she said. "But now, we are concluding our second impeachment trial in just 21 years."

Pointing to her vote to acquit President Bill Clinton during his impeachment trial in 1999, Collins said she has consistently believed that wrongdoing in office, even if proven, is not necessarily impeachable conduct.

"In the trial of President Clinton, I argued that in order to convict, 'We must conclude from the evidence presented to us with no room for doubt that our Constitution will be injured and our democracy suffer should the president remain in office one moment more,'" Collins said. "The House Managers adopted a similar threshold when they argued that President Trump’s conduct is so dangerous that he 'must not remain in power one moment longer.'"