Sen. Cory Gardner, who in October 2016 said of Donald Trump, “I cannot and will not support someone who brags about degrading and assaulting women,” this week said that he, in fact, can and will.

After two years of tightrope-walking between Trump critic and Trump cheerleader, Gardner, R-Colo., made his choice, saying he would support Trump’s re-election bid.

“I know what Kamala Harris and I know what Bernie Sanders will do to Colorado, and that’s why I’ll be supporting the president,” Gardner told the Independent Journal Review, referring to two Senate colleagues who could be vying for the Democratic nomination.

Trump celebrated getting Gardner’s endorsement Friday, tweeting: “Thank you to Senator Rob Portman and Senator Cory Gardner for the early and warm endorsement. We will ALL WIN in 2020 together!”

After audio of Donald Trump boasting about using his “star” status to sexually assault women surfaced in the closing weeks of the 2016 campaign, Gardner declared Trump unfit for the White House, calling him a “candidate whose flaws are beyond mere moral shortcomings and who shows a disgust for American character for dignity unbecoming of the Presidency.”

Since Trump took office, Gardner has been frustrated by many of Trump’s moves and incendiary comments, including his Justice Department’s crackdown on marijuana, his family-separation policy at the border and his equivocation of neo-Nazi violence in Charlottesville, Va.

At the same time, Gardner has fully leaned in to Trump’s domination of the Republican Party, voting with him more than 98 percent of the time, according to CQ, leading to speculation that Gardner has publicly disagreed with Trump only when it was convenient.

Gardner became the chairman of the National Republican Senatorial Committee after Trump’s election and spent the first two years of the Trump presidency working to add pro-Trump voices to the Senate.

Four GOP candidates in states that Trump carried in 2016 beat Democratic incumbents last year, boosting the Republican advantage in the upper chamber. Gardner gushed about Trump’s role in the outcome.

“We bucked history,” Gardner said in an interview on KNUS. “So, you know, the keeping of the majority in the midterm, I think, is historic. And President Trump went out and worked his tail off in a lot of these states.”

Now, Gardner has his own seat to worry about, and forecasters believe he should be worried.

His seat is routinely listed as the GOP’s most vulnerable in 2020, when he will be on the ballot with an unpopular president in a state that hasn’t selected a Republican for president since George W. Bush’s narrow victory there in 2004. Last year, Democrats swept all of Colorado’s statewide elections and re-took control of the state Senate.