People participate in the second March for Our Lives rally in support of gun control in front of the Washington Monument on Saturday. The demonstration is a successor to the 2018 march organized by student protesters after the mass shooting at a high school in Parkland, Fla. Gemunu Amarasinghe/Associated Press

WASHINGTON — Thousands of people rallied on the National Mall and across the United States on Saturday in a renewed push for gun control measures after recent deadly mass shootings from Uvalde, Texas, to Buffalo, New York, that activists say should compel Congress to act.

“Enough is enough,” District of Columbia Mayor Muriel Bowser told the second March for Our Lives rally in her city. “I speak as a mayor, a mom, and I speak for millions of Americans and America’s mayors who are demanding that Congress do its job. And its job is to protect us, to protect our children from gun violence.”

Speaker after speaker in Washington called on senators, who are seen as a major impediment to legislation, to act or face being voted out of office, especially given the shock to the nation’s conscience after 19 children and two teachers were killed May 31 at Robb Elementary School in Uvalde.

“If our government can’t do anything to stop 19 kids from being killed and slaughtered in their own school, and decapitated, it’s time to change who is in government,” said David Hogg, a survivor of the 2018 shooting that killed 17 students and staff at Marjory Stoneman Douglas High School in Parkland, Florida. He is also a co-founder of the March for Our Lives organization that was created after the shooting and held its first rally in Washington not long afterward.

“This time is different,” Hogg said, leading the crowd to repeat after him. He later led the crowd in chants of “Vote them out.”

Hundreds gathered at an amphitheater in Parkland, where Debra Hixon, whose husband, high school athletic director Chris Hixon, died in the shooting, said it is “all too easy” for young men to walk into stores and buy weapons.

“Going home to an empty bed and an empty seat at the table is a constant reminder that he is gone,” said Hixon, who now serves as a school board member. “We weren’t done making memories, sharing dreams and living life together. Gun violence ripped that away from my family.”

President Biden, who was in California when the Washington rally began, said his message to the demonstrators was “keep marching,” adding that he is “mildly optimistic” about legislative negotiations to address gun violence. Biden recently delivered an impassioned address to the nation in which he called for several steps, including raising the age limit for buying assault-style weapons.

In the Brooklyn borough of New York City, Mayor Eric Adams, who campaigned on reining in violence in the nation’s largest city, joined state Attorney General Letitia James, who is suing the National Rifle Association, in leading activists on a march toward the Brooklyn Bridge.

“Nothing happens in this country until young people stand up – not politicians,” James said.

Despite rain in the nation’s capital, thousands arrived on the monument grounds well before the rally began, holding up signs, including one that said “Children aren’t replaceable, senators are. Vote.” A middle school-age girl carried a sign that said, “I want to feel safe at school.”

Organizers hoped the second March for Our Lives rally would draw as many as 50,000 people to the Washington Monument. While that would be far less than the original 2018 march with more than 200,000 people, they focused this time on smaller marches at an estimated 300 locations.

The youth-led movement created after the Parkland shooting successfully pressured the Republican-dominated Florida state government to enact sweeping gun control changes. The group did not match that at the national level, but has persisted in advocating for gun restrictions since then, as well as participating in voter registration drives.

Survivors of mass shootings and other incidents of gun violence have lobbied legislators and testified on Capitol Hill this week. Among them was Miah Cerrillo, an 11-year-old girl who survived the shooting at Robb Elementary. She described for lawmakers how she covered herself with a dead classmate’s blood to avoid being shot.

On Tuesday, actor Matthew McConaughey appeared at the White House to press for gun legislation and made highly personal remarks about the violence in his hometown of Uvalde.

The House has passed bills to raise the age limit to buy semi-automatic weapons and establish federal “red flag” laws. But such initiatives have traditionally stalled or been heavily watered down in the Senate. Democratic and Republican senators had hoped to reach agreement this week on a framework for addressing the issue and talked Friday, but they had not announced