Hollywood celebrities lent their presence and political heft to the March for Our Lives gun control movement, and helped to rally Americans in a day of nationwide protest, by both donating large sums of money, as well as by showing up to march, speak and perform.

At Saturday’s march in Los Angeles, comedienne Amy Schumer, a showing of whose film Trainwreck was the scene of a 2015 shooting in a Louisiana theatre, spoke passionately against gun violence and the National Rifle Association (NRA) lobbying group at a gathering said to be 50,000-strong.

“How do they sleep at night? They call people like me ‘Hollywood liberals,’ like there’s something in it for us. Well, what’s in it for us is knowing we’re doing our part to keep our children alive,” she said.

​Schumer, a cousin of Democratic Senator Chuck Schumer of New York, also addressed the politicians who’ve taken money from the NRA.

“You’re digging the graves of the people that you are sworn to protect! Or you can make a little less money, and be able to look at yourself in the mirror with a little less blood on your hands!”

The comedienne dedicated her talk to the “17 fallen angels from Stoneman High, and the 20 little children from Sandy Hook”, referring to the recent high school shooting in Florida and the 2012 middle school shooting in Connecticut.

Schumer’s comments highlighted how fraught and complicated the politics can be for someone in her position. “Speaking up about this puts literal targets on our backs, and it narrows the people who will support our work. We sell half as many tickets because we’re standing up for what’s right!” she said to a roaring crowd, who shouted “Vote them out! Vote them out!’ in a furore that could well presage the mood of the 2018 mid-term elections in November.

The Los Angeles march was attended by droves of young people, many of whom had participated in the national school Walk-Out last week, and who paraded from downtown’s Broadway to City Hall to hear pop star Charlie Puth and Willow Smith, along with teen activists from Marjory Douglas Stoneman High in Florida, and LA’s Democratic Mayor Eric Garcetti, who is rumoured to be considering a run for the US presidency in 2020.

March for Our Lives – in pictures Show all 13 1 /13 March for Our Lives – in pictures March for Our Lives – in pictures Demonstrators chant during the protest for gun legislation and school safety AP March for Our Lives – in pictures Trevon ‘Tre’ Bosley, 19, of Chicago, the brother of Terrell Bosley who was killed in 2006 in a case of mistaken identity, speaks during the rally AP March for Our Lives – in pictures Marjory Stoneman Douglas High School student Delaney Tarr speaks at the rally AFP/Getty March for Our Lives – in pictures Protestors line the streets in Washington Getty Images March for Our Lives – in pictures People arrive for the March For Our Lives rally against gun violence in Washington, DC AFP/Getty March for Our Lives – in pictures Protestors carrying placards in Washington AFP/Getty March for Our Lives – in pictures Protestors hold up placards in Washington AFP/Getty March for Our Lives – in pictures Schoolchildren wear targets ahead of the rally Getty March for Our Lives – in pictures Attendees congregate in preparation for the march Getty March for Our Lives – in pictures Students brought a host of innovative placards AFP/Getty March for Our Lives – in pictures The movement’s main demand is the banning of assault rifles Getty March for Our Lives – in pictures Since the Florida shooting, students have called for urgent gun reform AFP/Getty March for Our Lives – in pictures In the wake of the Florida attack, President Donald Trump called for teachers to be armed AFP/Getty

Spotted in the crowd, actor and founder of the activist theatre group, The Actor’s Gang, Tim Robbins tersely explained to The Independent why he had come to march: “I don’t accept living in a country where a six-year-old has to do a shooter drill. Or that a kid in kindergarden, before learning how to read, learns how to hide in a closet from an imagined scenario.”

Protest signs along the route read, “I go to school to get A’s, not PTSD,” “Math Before Bloodbath,” and “My Outrage Won’t Fit On This Sign.”

Former First Lady of California Maria Shriver, ex-wife of actor and former governor Arnold Schwarzenegger, also marched, and told The Independent she thought the experience was “energising”. Though there have been anti-gun protests before, she said, “it feels different this time”.

“This is a moment. I’m heartened that even a lot of gun owners want their voices heard, and that they’re for sensible gun reform,” she said, referencing the fact that the US’s Second Amendment allows for “the right to bear arms”.

When asked, however, about her ex-husband’s record in office on gun control (never mind his depiction of gun violence in Hollywood films), Shriver was dismissive. “I’m here to talk about right now” (for the record, Schwarzenegger has suggested that guns in films are “just entertainment”).

A total of $2m (£1.4m) has been raised for the March for Our Lives movement from other Hollywood celebrities, including Oprah Winfrey, George Clooney, Steven Spielberg.

NRA TV video ahead of #MarchForOurLives