Sen.(R-Maine) announced on Tuesday that she will vote to acquiton the two House-passed articles of impeachment.

"I do not believe that the House has met its burden of showing that the president's conduct, however flawed, warrants the extreme step of immediate removal from office," Collins said from the Senate floor.

Collins told reporters after her speech that she had a "much easier" time making a decision on the second article of impeachment compared to the first article of impeachment.

In regard to the first article, abuse of power, Collins argued that Democrats did "not even attempt to assert that the president committed a crime."

"While I do not believe that conviction of a president requires a criminal act, the high bar for removal from office is perhaps even higher when impeachment is for a difficult-to-define noncriminal act," she said.

Collins is one of several senators who have been seen as possible swing votes on Trump's conviction or acquittal.

Collins is one of 15 senators who were also in the chamber during the 1999 Clinton impeachment trial. She voted at the time to find Clinton not guilty of both charges.

She walked reporters through her process for coming to a decision, saying she reviewed her files from the 1999 trial and the rules resolution for that proceeding; did historical research, including consulting what the Founding Fathers said about "high crimes and misdemeanors"; reread the House transcripts; and consulted with the legal division within the Congressional Research Service. "From there it became an issue of deciding whether the misconduct that did occur reached the very high bar that the founders established," she said. "In the end I felt it did not." Collins has been the subject of intense scrutiny during, as well as in the lead up to, Trump's trial.

"It was wrong for President Trump to mention former Vice President Biden on that phone call, and it was wrong for him to ask a foreign country to investigate a political rival," Collins said.The House voted to impeach Trump on two articles of impeachment: abuse of power in his actions toward Ukraine and obstructing Congress's investigation into those actions.