WASHINGTON (AP) - A celebratory crowd of thousands bundled up on a chilly Tuesday afternoon to watch President Joe Biden sign gay marriage legislation into law, a joyful ceremony that was tempered by the backdrop of an ongoing conservative backlash over gender issues.

“This law and the love it defends strike a blow against hate in all its forms,” Biden said on the South Lawn of the White House. “And that’s why this law matters to every single American.”

Singers Sam Smith and Cyndi Lauper performed. Vice President Kamala Harris recalled officiating at a lesbian wedding in San Francisco. And the White House played a recording of Biden’s television interview from a decade ago, when he caused a political furor by unexpectedly disclosing his support for gay marriage. Biden was vice president at the time, and President Barack Obama had not yet endorsed the idea.

“I got in trouble,” Biden joked of that moment. Three days later, Obama himself publicly endorsed gay marriage.

Lawmakers from both parties attended Tuesday’s ceremony, reflecting the growing acceptance of same-sex unions, once among the country’s most contentious issues.

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

“Thanks to the millions out there who spent years pushing for change, and thanks to the dogged work of my colleagues, my grandchild will get to live in a world that respects and honors their mothers’ marriage,” he said.

House Speaker Nancy Pelosi told the crowd that “inside maneuvering only takes us so far,” and she thanked activists adding impetus with “your impatience, your persistence and your patriotism.”