With his signature, the president expanded his footprint on equality issues at a time when advocates fear the Supreme Court could revisit the ruling that made same-sex marriage a right nationwide more than seven years ago. The historic legislation was seen as a watershed moment in American society, the culmination of a political shift that Biden, years ago, deemed inevitable.

The landmark bipartisan legislation passed the House last week in a 258-169 vote, with 39 Republicans supporting the measure. Its passage there followed months of negotiations in the Senate, where it was led by Sens. Tammy Baldwin (D-Wis.), Susan Collins (R-Maine), Rob Portman (R-Ohio), Kyrsten Sinema (I-Ariz.) and Thom Tillis (R-N.C.). The measure passed in the Senate with the backing of 12 Republicans.

House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer kicked off Tuesday’s event at the White House, and Biden praised the party leaders and other lawmakers who worked on the bill.

“It’s one thing for the Supreme Court to rule on a case, but it’s another thing entirely for elected representatives of the people to take a vote on the floor of the United States Congress and say loudly and clearly, love is love. Right is right. Justice is justice,” Biden said.

Attendees held cellphones aloft, taking photos. Earlier, many danced to the pre-show soundtrack playing on the loudspeakers. Some front-row attendees waved small rainbow pride flags as the crowd cheered. Singer Sam Smith performed “Stay with Me,” and musician and activist Cyndi Lauper sang “True Colors” before the president’s appearance.

Biden was energetic as he walked up to the podium. He chuckled, telling the crowd that it might remember “on a certain TV show” 10 years ago when he declared his support for same-sex marriage. “I got in trouble,” he noted.

In 2012, Chad Griffin led the American Foundation for Equal Rights — and was about to become president of the Human Rights Campaign — when he spoke with the then-vice president at a Los Angeles fundraiser hosted by a same-sex couple, whose two young children were playing nearby. Griffin was the one who asked Biden about his views on same-sex unions — and Biden’s response at the event was one he echoed two weeks later on NBC’s “Meet the Press.” Biden said it came down to one question: “Who do you love?”

“I am absolutely comfortable with the fact that men marrying men, women marrying women, and heterosexual men and women marrying another are entitled to the same exact rights, all the civil rights, all the civil liberties,” Biden said at the time, setting off a firestorm in the White House. President Barack Obama came out in support of the issue three days later.

That interview became a turning point for Biden, who almost 20 years earlier had voted for the 1996 Defense of Marriage Act, which defined marriage as a union only between a man and a woman. It helped that Biden was known for being a practicing Catholic and very involved with his extended family. That made a difference when he spoke to his audiences — “voters at all levels — union workers, blue-collar workers, and folks across the political spectrum,” Griffin said.

He watched Biden’s arc, from that day at the fundraiser, to publicly declaring his support two weeks later on television, to standing with the president Tuesday at the bill signing.

“It is more than appropriate that President Biden is the one that signs the marriage bill into law because of the very early role that he played in getting marriage across the finish line in terms of public opinion, in terms of moving the needle in the country on support for marriage equality,” he said.

Biden’s equality push was also evident in his early days as president. He signed an executive order to combat discrimination across the federal government on Day One. That same week, he rescinded his predecessor’s ban on transgender service members in the military. Fourteen percent of Biden’s appointees identify as LGBTQ, according to the White House.

The president used Tuesday’s celebration to acknowledge the Supreme Court’s overturning of Roe v. Wade, and the resulting threats to other rights like access to contraception. He warned the crowd that more challenges lay ahead.

“When hospitals, libraries and community centers are threatened and intimidated because they support LGBTQ children and families, we have to speak out. We must stop the hate and violence,” Biden said, referencing the shooting at an LGBTQ nightclub in Colorado Springs, Colo., last month. “We need to challenge the hundreds of callous and cynical laws introduced in the states, targeting transgender children, terrifying families and criminalizing doctors who give children the care they need. We have to protect these children, so they know they are loved.”

Jonathan Lemire and Eli Stokols contributed to this report.