Sen. Susan Collins, R-Maine, center, departs as Republican senators leave a closed-door strategy session at the Capitol in Washington, Tuesday, Feb. 4, 2020. They are expected to acquit President Donald Trump tomorrow on impeachment charges of abuse of power and obstruction of Congress. Credit: J. Scott Applewhite | AP

U.S. Sen. Susan Collins told CBS News on Tuesday she thinks President Donald Trump has learned from the impeachment saga ahead of a Wednesday vote where the chamber is expected to acquit the president on both articles of impeachment.

Collins announced in a speech on the Senate floor Tuesday afternoon that she would vote against removing the president from office, arguing that the allegations against him do not rise to the level of high crimes and misdemeanors outlined in the Constitution.

The articles of impeachment stemmed from a July phone call where Trump asked the Ukraine leader to investigate former Vice President Joe Biden, one of the Democrats competing for the nomination to take on Trump later this year. House Democrats put forward impeachment articles alleging Trump abused his power with the call and then obstructed a House investigation.

In a pre-taped interview with CBS, she said that she believed the president would not seek foreign assistance again, saying Trump had “learned from this case” and that impeachment was “a pretty big lesson.”

Trump has long described his phone call with the Ukrainian president as a “perfect phone call,” a characterization that he repeated in a tweet last month and in an off-the-record briefing with news anchors on Wednesday as reported by The Washington Post after being informed of Collins’ comments.

Collins said in the interview that a president “should not be asking a foreign country to investigate a political rival.”

“That is just improper,” she said. “It was far from a perfect call.”

Collins declined to support Trump in the 2016 election after he clinched the Republican nomination, writing that August that he “seems incapable of change or growth.”

Sen. Angus King, an independent who caucuses with Democrats and announced Tuesday he will vote to convict the president, argued that Trump was “attempting to undermine” the 2020 election “and he gives every indication that he will continue to do so.”

On the political consequences of her decision on impeachment, Collins said she was sure that “there are going to be people unhappy” with her in Maine as she faces a 2020 re-election challenge from national Democrats but that her job was to consider constitutional standards to remove a president from office rather than how the vote would affect her political future.

Four Democrats — Maine House Speaker Sara Gideon, progressive lobbyist Betsy Sweet, former Google executive Ross LaJeunesse and lawyer Bre Kidman — are vying in a June primary for the nomination to take on Collins. Green candidate Lisa Savage and three independents are gathering signatures in their attempts to get on the November ballot.