The Senate on Tuesday approved legislation to codify protections for same-sex and interracial marriages, marking a historic win for Democrats anxious to secure the rights amid growing concern that a conservative Supreme Court majority could take them away.
The final vote was 61 to 36.
"What a great day," Senate Majority Leader Chuck Schumer said soon after passage. The bill sparked rare applause on the floor.
The Respect for Marriage Act would not require any state to issue a marriage license contrary to its laws but would mandate that states recognize lawfully granted marriages performed in other states, including same-sex and interracial unions.
The bill had been largely expected to pass after it earned essential support from 12 Republicans during a key test vote just before Thanksgiving, putting it on a glide path to President Joe Biden's desk later this month. The bill next heads to the House, which is expected to vote on it next week -- as early as Tuesday -- before Biden signs it. In a statement Tuesday night, he said he would "promptly and proudly" do so.
"The United States is on the brink of reaffirming a fundamental truth: love is love, and Americans should have the right to marry the person they love," he said.
Codifying same-sex marriage into federal law became a top priority for Democrats in light of the Supreme Court's decision in June to overrule its 1973 Roe v. Wade decision guaranteeing a constitutional right to abortion nationwide.
In floor remarks Tuesday afternoon, Schumer celebrated the bill, which he said ensures rights of LGBTQ people won't be "trampled."
"In many ways, the story of America has been a difficult, but inexorable march toward greater equality. Sometimes we've taken steps forward, other times, unfortunately, we've taken disturbing steps backward, but today, after months of hard work, after many rounds of bipartisan talks, and after many doubts that we could even reach this point, wea re taking the momentous step forward for greater justice for LGBTQ Americans," Schumer said.
Schumer and other Democrats have argued that a concurring opinion by Justice Clarence Thomas in the June decision, in which he said the court "should reconsider" granting a nationwide right to gay marriage, put the rights of LGBTQ Americans in question.
For Schumer, and other senators with loved ones who are a part of the LGBTQ community, the matter is personal. Schumer's daughter is married to her wife. On Tuesday, he appeared on the Senate floor wearing a tie that he said he wore at his daughter's wedding.
Schumer said that after Justice Ruth Bader Ginsburg died two years ago, his daughter was concerned her marriage could be in jeopardy. Now, two years later, and with the Congress poised to act, his daughter is expecting a child.
"I want them to raise their child with all the love and security that every child deserves," Schumer said. "And the bill we are passing today will ensure their rights won't be trample upon simply because they're in a same-sex marriage."
The original 12 Republicans from the first procedural vote stuck with their decision on Tuesday, despite pressure to reverse course from conservative groups and other lawmakers.
Those 12 were: Susan Collins of Maine, Rob Portman of Ohio, Thom Tillis of North Carolina, Mitt Romney of Utah, Shelley Moore Capito of West Virginia, Cynthia Lummis of Wyoming, Dan Sullivan of Alaska, Roy Blunt of Missouri, Richard Burr of North Carolina, Joni Ernst of Iowa, Todd Young of Indiana and Lisa Murkowski of Alaska.
"I know that it's not been easy but they've done the right thing," Collins, one of the bill's co-sponsors, said Tuesday of her GOP colleagues ahead of the final vote.
Lummis, largely seen as one of the bill's most surprising supporters, described the days since her initial yes vote as a "painful exercise in accepting admonishment and fairly brutal self soul searching." She took pains to explain that while her personal religious beliefs preclude same-sex marriage, but said she still intends to support the bill.
"For the sake of our nation's today and its survival, we do well by taking this step, not embracing or validating each other's devoutly held views but by the simple act of tolerating them," Lummis said.
GLAAD celebrated the passage, with its president and CEO, Sarah Kate Ellis, saying in a statement that it "sends a message of equal protection, dignity, and respect for all same-sex and interracial couples who want to share in the love and commitment of marriage."
The Respect for Marriage Act would "require the federal government to recognize a marriage between two individuals if the marriage was valid in the state where it was performed," according to a summary from the bill's sponsors, including Congress' first openly bisexual woman in the Senate, Kyrsten Sinema, D-Ariz., along with Collins, Portman and Tillis.
The legislation comes after months of behind the scenes coalition-building between Democrats and a group of Republican negotiators. Despite the crucial GOP support, the legislation was opposed by a large contingent of Republicans, some who have deemed it unnecessary.
"I think it's pretty telling that Sen. Schumer puts a bill on the floor to reaffirm what is already a constitutional right of same-sex marriage, which is not under any imminent threat, and continues to ignore national security and not take up the defense authorization bill," Sen. John Cornyn, R-Texas, said earlier this month.
During the pre-Thanksgiving test vote, Senate Republican Leader Mitch McConnell voted with the majority of his party to oppose the bill -- and vote no again on Tuesday.
The House passed a similar version of this legislation earlier this year, with 47 Republicans supporting it. The Senate version includes new language to ease some GOP concerns about religious freedom.
ABC News' Ben Gittleson and Robert Zepeda contributed to this report.