Joe Biden, as vice president, administers the Senate oath to U.S. Sen. Susan Collins, R-Maine, during a ceremonial re-enactment swearing-in ceremony, Tuesday, Jan. 6, 2015, in the Old Senate Chamber on Capitol Hill in Washington. Collins' husband Tom Daffron is at center. Credit: Susan Walsh / AP

U.S. Sen. Susan Collins and President-elect Joe Biden are friends. After prevailing in bruising elections last week, they will be linked in the next phase of their long careers.

After a tumultuous four years under President Donald Trump, during which the Maine Republican went from one of the most popular senators in the country to one of the least by approval rating, Collins was re-elected decisively last week with 51 percent of the vote, buoyed by many voters who split their tickets to also hand Biden, a Democrat, a statewide majority.

With Biden in the White House, Collins will no longer face regular questions about Trump’s irregular remarks and conduct. Her status as one of the most moderate members of her party and her long-standing relationship with Biden mean she could be someone the Democratic president-elect turns to as he seeks compromise with a Senate likely controlled by Republicans.

It is a familiar position for Collins, who has frequently been a swing vote in her career, but it will come after she survived a nationally targeted election in which Democrats spent $130 million in a bid to oust her. She instead won by 9 percentage points over House Speaker Sara Gideon, D-Freeport, nearly mirroring Biden’s winning margin in the Democratic-leaning state.

“They served together for years. They have a very, very collegial relationship,” said Bobby Reynolds, a former Collins aide. “They both have great deference to the traditions of the Senate and above all, they know their job now is to govern.”

Biden and Collins are Irish Catholics who served in the Senate together for 12 years. In a 2016 floor speech at the end of Biden’s vice presidency, Collins highlighted her friendship with him, characterizing him as someone who “never alienated those of us on the other side of the aisle.”

“It is often said that if you don’t love Joe Biden, it is time for some serious introspection,” Collins said.

The praise has gone both ways. In a 2017 video congratulating Collins as the recipient of a Irish heritage award, Biden glowingly characterized her as “a woman who embodies the sacrifice for your country and public service.”

“You all know Susan well, there’s not much more I can tell you about her except I’m crazy about her,” Biden said.

Biden endorsed Gideon, though his statement was relatively milquetoast. Collins told Maine Public that Biden called her last week to congratulate her on her victory. Neither her spokespeople nor those for Biden’s campaign responded to questions on what they discussed. During her campaign, she never said whom she supported for president but noted Biden’s shift to the left in Republican circles.

Senate control will depend on the outcome of two runoffs in Georgia in early January, when Republican Sens. David Perdue and Kelly Loeffler will face Democrats Jon Ossoff and Raphael Warnock, respectively. Democrats would have to win both to reach 50 seats in the Senate, at which point Vice President-elect Kamala Harris would be the tie-breaking vote in the chamber.

What Biden and the Senate will advance depends greatly on partisan control. Collins decried attacks from Democratic groups during her Senate campaign this year, frequently singling out Senate Minority Leader Chuck Schumer, D-New York, for attacks in the race. While the two may have a badly strained relationship, Collins maintains strong ties to some Democrats including Sen. Joe Manchin, D-West Virginia, another moderate who may play a pivotal role.

Many Senate Republicans have refused to recognize Biden as the winner of the presidential election, with only Collins and a handful of others publicly acknowledging his victory. Trump has refused to concede while pushing unsupported claims of widespread voter fraud.

Biden is still on track to assume office in mid-January. Senate Majority Leader Mitch McConnell of Kentucky could exert influence over Cabinet picks if Republicans maintain the majority. Biden’s transition team is considering more centrist picks as a result, according to Axios.

Collins generally supports presidential nominees, saying they have wide latitude to choose their advisers. When former President Barack Obama took over in 2009, the Democrat got Collins’ support for five of his six Cabinet picks through late April, opposing one for personal tax return issues. She voted against two of Trump’s first round of nominees in 2017.

“I’m sure that folks who saw that as a real detriment under a Republican president will see that as a positive thing now,” said former Maine Senate President Mike Thibodeau, R-Winterport, a Collins ally. “She’ll be even-handed.”

But even as Democrats are likely to seek her vote, Collins’ victory last week does not mean she has won over some of her loudest critics in Maine, though progressives who have spent the past few years protesting her are likely to change direction with Biden and not Trump in office.

Those activists will look to ensure that Collins’ office hears from like-minded Mainers, said Marie Follayttar of Scarborough, director of Mainers for Accountable Leadership, a progressive group that campaigned heavily against the senator. The vigor and tenor of that effort may depend on the Senate makeup.

“Ultimately, she still serves the people,” Follayttar said.

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