Sen. Susan Collins, R-Maine, speaks to reporters on Wednesday, May 4, 2022. Credit: J. Scott Applewhite / AP

U.S. Sen. Susan Collins is optimistic that a bill she is sponsoring to enshrine the right to same-sex marriage will get enough support from fellow Republicans to pass, she said Wednesday.

The bill’s potential passage reflects rapid changes in public perceptions toward same-sex marriage, particularly since Maine voted for it in 2012. It also reflects increasing concern that the federal right enshrined by the U.S. Supreme Court three years later could be taken away after the June high court decision stripping federal abortion rights.

“I’m never confident until the roll is called, but we’re making good progress,” the Maine senator told reporters in Washington on Wednesday. “There’s a lot of sincere interest.”

The bill gained steam after conservative Justice Clarence Thomas argued in a concurring opinion within the abortion ruling that the Supreme Court should also consider overturning a 2015 opinion that recognized a constitutional right to same-sex marriage.

Sen. Tammy Baldwin, D-Wisconsin, the first person elected to the Senate after coming out as LGBTQ, is sponsoring the measure with Collins as the lead Republican behind it. The two called for passage of the bill in a Washington Post Op-Ed on Tuesday.

Collins said Wednesday that she was looking at amending the bill to assuage conservative fears that the measure would infringe on religious liberty or allow for polygamous marriages. A few other Republicans have gone on the record saying they either will or will likely back it, including Sens. Lisa Murkowski of Alaska, Rob Portman of Ohio and Thom Tillis of North Carolina.

It will need 10 Republicans to win the 60 votes necessary for a filibuster-proof majority in the Senate. Sen. Ron Johnson of Wisconsin, who once said he would back the bill, said Wednesday that he would vote against it. A version of the measure passed the Democratic-led House in July with 47 Republicans in favor.

Some Democrats have toyed with adding the legislation to a bill that would temporarily fund the government before the 2022 fiscal year ends on Sept. 30. Baldwin and Collins oppose that, saying it will politicize the measure further.

Collins was the fourth Republican senator to publicly support same-sex marriage in 2014, though it came nearly two years after Maine legalized it by referendum. She has long stood out in her party on LGBTQ rights, once angering social conservatives by fundraising at a Portland gay bar while running for governor in 1994.

The LGBTQ-rights Human Rights Campaign endorsed her in 2014, but her relationship with socially liberal groups eroded during the tenure of former President Donald Trump. Collins voted for two of his three Supreme Court nominees.

The Human Rights Campaign cited her support for Justice Brett Kavanaugh in a 2020 endorsement of Democrat Sara Gideon, while the evangelical Christian Civic League of Maine backed Collins despite differences on social issues.

In 2009, a majority of Maine voters opposed legalizing same-sex marriage, with 53 percent voting strike down a marriage-equality bill passed signed into law by then-Gov. John Baldacci. But just three years later, 53 percent voted the other way, legalizing same-sex marriage.

Since that vote and the 2015 high court ruling, the issue has been mostly moot in Maine. The Christian Civic League has criticized the measure but did not respond to a request for comment on it. Neither did EqualityMaine, the state’s largest LGBTQ-rights organization.

The bill is an important step to codify same-sex marriage rights, said David Stacy, the Human Rights Campaign’s government affairs director. While he doesn’t believe the constitutional right to same-sex marriage is at “imminent risk,” he said the bill is necessary.

He expects that it will get 10 Republican votes in the Senate, noting that the success of previous LGBTQ-rights bills has shown party members will not always announce they are voting for one beforehand. Republicans often have a “strong social conservative” part of their base that they keep in mind while gaming out votes, Stacy said.

“It’s great to see Susan Collins taking a leadership role on this,” he said. “Her stepping forward and helping to try to get this done is something that Mainers should be proud of.”