WASHINGTON (AP) — President Joe Biden is inviting thousands to celebrate at the White House on Tuesday as he signs into law gay marriage legislation before a bipartisan crowd that reflects growing acceptance of same-sex unions.

Lawmakers from both parties will be there, as will first lady Jill Biden and Vice President Kamala Harris and her husband, Doug Emhoff. Singer Cyndi Lauper, a longtime advocate for gay rights, will perform.

“For once, our families, mine and a lot of my friends — and people you know, sometimes your neighbors — we can rest easy tonight, because our families are validated,” she said at the White House briefing room before the ceremony.

Senate Majority Leader Chuck Schumer, D-N.Y., said he would wear the same purple tie to the ceremony that he wore to his daughter’s wedding. His daughter and her wife are expecting their first child in the spring.

“Thanks to the dogged work of many of my colleagues, my grandchild will live in a world that will respect and honor their mothers’ marriage,” Schumer said.

The triumphant mood will play out against the backdrop of a right-wing backlash over gender issues, which has alarmed gay and transgender people and their advocates.

Among the attendees will be the owner of Club Q, a gay nightclub in Colorado where five people were killed in a shooting last month, and two survivors of the attack. The suspect has been charged with hate crimes.

Plaintiffs from lawsuits that originally helped secure the nationwide right to gay marriage are also expected to be there, according to the White House.

“It’s not lost on me that our struggle for freedom hasn’t been achieved,” said Kelley Robinson, president of the Human Rights Campaign. “But this is a huge step forward, and we have to celebrate the victories we achieve and use that to fuel the future of the fight.”

Robinson is attending the ceremony with her wife and 1-year-old child.

“Our kids are watching this moment,” she said. “It’s very special to have them here and show them that we’re on the right side of history.”

The new law is intended to safeguard gay marriages if the U.S. Supreme Court ever reverses Obergefell v. Hodges, its 2015 decision legalizing same-sex unions nationwide. The new law also protects interracial marriages. In 1967, the Supreme Court in Loving v. Virginia struck down laws in 16 states barring interracial marriage.

“Congress has restored a measure of security to millions of marriages and families,” Biden said in a statement when the legislation passed last week. “They have also provided hope and dignity to millions of young people across this country who can grow up knowing that their government will recognize and respect the families they build.”

The signing will mark the culmination of a monthslong bipartisan effort sparked by the Supreme Court’s decision in June to overturn Roe v. Wade, the 1973 ruling that made abortion available across the country.

In a concurring opinion in the case that overturned Roe, Justice Clarence Thomas suggested revisiting other decisions, including the legalization of gay marriage, generating fear that more civil rights could be imperiled by the court’s conservative majority. Thomas did not include interracial marriage with other cases he said should be reconsidered.

Lawmakers crafted a compromise that was intended to assuage conservative concerns about religious liberty, such as ensuring churches could still refuse to perform gay marriages.

In addition, states will not be required to issue marriage licenses to same-sex couples. But they will be required to recognize marriages conducted elsewhere in the country.

A majority of Republicans in Congress still voted against the legislation. However, enough supported it to sidestep a filibuster in the Senate and ensure its passage.

“Together, we showed that it’s possible for Democrats and Republicans to come together to safeguard our most fundamental rights,” Biden said.

Tuesday’s ceremony will mark another chapter in Biden’s legacy on gay rights.

He memorably — and unexpectedly — endorsed same-sex unions in a television interview in 2012, when he was vice president. Days later, President Barack Obama announced that he also supported gay marriage.

Attendees will be given a card commemorating Biden’s comments from his 2012 interview.

“What this is all about is a simple proposition: Who do you love?” Biden said on NBC’s “Meet the Press” a decade ago. “Who do you love and will you be loyal to the person you love? And that is what people are finding out is what all marriages at their root are about.”

A Gallup poll showed only 27% of U.S. adults supported same-sex unions in 1996, when President Bill Clinton signed the Defense of Marriage Act, which said the federal government would only recognize heterosexual marriages. Biden voted for the legislation.

By the time of Biden’s 2012 interview, gay marriage remained controversial, but support had expanded to roughly half of U.S. adults, according to Gallup. Earlier this year, 71% said same-sex unions should be recognized by law.

Biden has pushed to expand LGBT rights since taking office. He reversed President Donald Trump’s efforts to strip transgender people of anti-discrimination protections. His administration includes the first openly gay Cabinet member, Transportation Secretary Pete Buttigieg, and the first transgender person to receive Senate confirmation, Assistant Secretary for Health Rachel Levine.