Issuing an emotional plea following the South Carolina church shooting, Hillary Rodham Clinton called for "common-sense" gun reforms and a national reckoning with the persistent problem of "institutional racism."
Three days after nine black church members were gunned down in Charleston, Clinton said the country must take steps to keep guns from criminals and the mentally ill.
Regulations, she said, can be passed while still respecting the Second Amendment and "respecting responsible gun owners."
"The politics on this issue have been poisoned, but we can't give up," she told the U.S. Conference of Mayors in San Francisco on Saturday. "The stakes are too high. The costs are too dear."
In 2013 Congress rejected legislation that would have expanded background checks on firearm sales and banned some semi-automatic weapons.
President Barack Obama has blamed the continued national political inaction on the issue on the influence of the National Rifle Association.
While Clinton did not propose any specific legislation in her address, she's previously supported limits on gun sales and extending the assault weapons ban.
On Friday, former Maryland Governor Martin O'Malley, who's challenging Clinton for the Democratic Party nomination, called for an assault weapons ban, stricter background checks and tougher requirements to buy a gun.
"I'm pissed," he wrote in an email to supporters. "It's time we called this what it is: a national crisis."
Clinton's remarks also marked a forceful entry into the heated topic of race relations, an issue that's become a major theme of her campaign. Clinton called race a "deep fault line" in America, noting that "millions of people of color still experience racism in their everyday lives."
The problem of racism was not limited to "kooks and klansman," she said, but included the off-hand, off-color joke; whites scared of young black men and not speaking up against poverty and discrimination.
In previous appearances, Clinton has taken up a number of issues that are important to African-Americans, calling for changes to the criminal justice system, voting laws and assistance for minority small business owners. Her campaign is trying to motivate the coalition of minority, young and liberal voters that twice elected Obama to the White House.
"We can't hide from any of these hard truths about race and justice in America," she said. "We have to name them and then own them and then change them."
Clinton's address to the country's mayors was her last stop on a cross-country tour, largely of early voting states, after formally launching her campaign a week ago in New York City. She spent Friday raising money at three fundraisers in Los Angeles, including one hosted by actor Tobey Maguire.