Several leading Republican presidential candidates, including former President Donald J. Trump and Gov. Ron DeSantis of Florida, were converging on Philadelphia on Friday to rally conservative activists around a shared agenda of restricting transgender rights and limiting how race and L.G.B.T.Q. issues are discussed in schools.
Mr. DeSantis was the first to speak at a gathering of the newest powerhouse in social conservative circles, Moms for Liberty, which began as a small group of far-right suburban mothers but has quickly gained national influence.
“What we’ve seen across this country in recent years has awakened the most powerful political force in this country: mama bears,” Mr. DeSantis told the crowd of hundreds, to roars of applause. “We’ve done so much on these issues in Florida, and I will do all this as the next president.”
Shortly after he spoke, the Supreme Court gave the conservative movement more victories with two rulings, one striking down President Biden’s program to relieve student loan debt and the other backing a web designer who had refused to provide services for same-sex marriages.
Mr. DeSantis headlined Moms for Liberty’s opening breakfast event, a nod to the group’s founding in his home state in 2021. Its national rise — it says it now has 275 chapters in 45 states — has coincided with the Florida governor’s ascension in right-wing circles as he pushed legislation to restrict discussions of so-called critical race theory and sexuality and gender in public schools.
Mr. DeSantis’s pitch to social conservatives centers on the idea that he, not Mr. Trump, is the most likely to turn their priorities into legislation. The former president, who was scheduled to speak later in the afternoon, leads Mr. DeSantis by a wide margin in the polls.
In a 20-minute address before the friendliest of crowds, Mr. DeSantis highlighted legislation he championed in Florida banning gender transition care for minors, preventing teachers from asking students for their preferred pronouns and prohibiting transgender girls from competing in girls’ sports.
Another Republican presidential candidate, Nikki Haley, a former United Nations ambassador and governor of South Carolina, struck a different tone later Friday morning. Lacking the kind of recent legislative record that Mr. DeSantis can point to, she instead drew on her experiences as a mother: She directly called herself a “mom for liberty” and often invoked her children.
“Moms care about a lot of things — it’s not just schools,” Ms. Haley said. “We care about the debt, we care about crime, we care about national security, we care about the border. Moms care about everything.”
Calling itself a “parental rights group,” Moms for Liberty has built its platform on a host of contentious issues centering on children — a focus that many on the right believe could help unite the Republican Party’s split factions in 2024.
The group has railed against public health mandates related to the coronavirus and against school materials on L.G.B.T.Q. and race-related subjects. Its members regularly protest at meetings of school boards and have sought to take them over. The group has also spearheaded the removal of books its members deem inappropriate for K-12 students.
Along the way, Moms for Liberty has drawn a backlash. The Southern Poverty Law Center, a left-leaning civil rights organization, has labeled it an extremist group, saying that it “commonly propagates conspiracy theories about public schools attempting to indoctrinate and sexualize children with a progressive Marxist curriculum.”
Before the group’s conference in Philadelphia, a half-dozen scholarly groups criticized the Museum of the American Revolution for allowing Moms for Liberty to hold some of its events there, including the opening reception.
Mayor Jim Kenney of Philadelphia, a Democrat, said on Thursday that “as a welcoming and inclusive city, we find this group’s beliefs and values problematic.”
Protesters gathered outside the conference venues beginning Thursday night and stretching into Friday, picketing the downtown Marriott hotel, where Mr. DeSantis, Ms. Haley and other candidates were speaking.
The schedule for Saturday included a session led by KrisAnne Hall, a former prosecutor and conservative public speaker with past ties to the Oath Keepers, a far-right militia that helped orchestrate the Capitol attack on Jan. 6, 2021.
Sessions at the event bridged a wide range of subjects, including exploration of “dark money’s infiltration in education” and discussions about the Federalist Papers. But the presidential candidates were the main draw.
Two other Republicans — Asa Hutchinson, a former governor of Arkansas, and Vivek Ramaswamy, an entrepreneur and activist — were slated to speak on Saturday. Robert F. Kennedy Jr., a Democratic presidential candidate and prominent vaccine skeptic, had been scheduled to speak on Sunday but backed out earlier in the week, citing a “family holiday obligation.”
