WASHINGTON (AP) — Democratic Sen. Joe Manchin on Sunday endorsed Republican colleague Lisa Murkowski for reelection, crossing party lines to back the incumbent from Alaska who faces a primary challenger supported by former President Donald Trump.

The conservative West Virginia lawmaker said he has teamed well with Murkowski in the 50-50 Senate to build bipartisan support for legislation such as President Joe Biden’s infrastructure law. He said Alaska and the Senate are well-served with her in office.

“It’s hypocritical to basically work with a person day in and day out and then, when they’re in cycle, you’re supposed to be against them because they have an R or D by their name,” said Manchin, who appeared with Murkowski on CNN’s “State of the Union” to promote the values of bipartisanship.

“Alaska could only be so lucky to have her continue to serve them,” he said.

Murkowski faces GOP primary challenger Kelly Tshibaka, who has support from Trump and Alaska Republican party leaders but who significantly trails the incumbent in fundraising. A Democrat has yet to enter the race; the last state’s last Democratic senator, Mark Begich, lost reelection in 2014.

It isn’t the first time that Manchin has bucked his party’s political operation. In 2020, he endorsed Sen. Susan Collins, R-Maine, in her reelection bid. Manchin had indicated last April that he would support Murkowski if she chose to run again this year.

Murkowski is one of seven Republican senators who voted to convict Trump in his second impeachment trial for his role in stoking the Jan. 6 Capitol insurrection. Her reelection bid plays up her credentials as a centrist in the Senate, working across party lines to “stand up to any politician or special interest that threatens our way of life.”

A member of the Senate since 2002, Murkowski lost the Republican primary for her seat in 2010 but ultimately won after launching a successful write-in campaign. She’s joined Democrats several times on high-profile votes, including opposing Trump’s effort to repeal President Barack Obama’s health law in 2017 and her 2018 refusal to vote to confirm Brett Kavanaugh as a Supreme Court justice.

Murkowski said Sunday she as well would support Manchin, who is up for reelection in 2024.

“If he’s running, I’m endorsing him,” she said.

Manchin has drawn ire from the progressive wing of his party over his reluctance to back broad climate and social safety net legislation that Biden envisioned would pass with support from all 50 Democratic senators. After initially indicating he could support a version of that bill, Manchin announced in December that he would not back the effort and that the legislation in its present form was dead.

On Sunday, Manchin indicated he recently talked to Biden but said the topic didn’t really come up because of the need for separate action by Feb. 18 on a separate funding bill.

He reiterated a desire to pass smaller pieces of Biden’s proposal with input and support from Republicans. “These are major changes,” Manchin said. “It is going to change society as we know it.”