In the 2016 campaign, Clinton has fought for a raft of gun reforms. But she hasn't always been as strident an advocate for gun control.
In the 1990s, she was a fierce supporter for the landmark Brady Bill restrictions. But in the 2000s, she didn't push the issue, and even slammed then-Sen. Barack Obama's criticism of people who "cling to guns or religion" in the 2008 presidential primary. And now, after a rash of mass shootings, she's the Democratic standard-bearer on a renewed gun control push.
Testifying in a Senate committee in 1993 amid her health care reform push, Clinton told Sen. Bill Bradley, D-New Jersey, she was "all for" his proposed 25% tax on handguns and $2,500 licensing fees for gun dealers.
"Speaking personally -- and that's all I can do with respect to your second proposal -- I'm all for that," she had said. "I just don't know what else we're going to do to try to figure out how to get some handle on this violence."
She kept up her advocacy through the decade, recording robo-calls opposing a Missouri concealed carry ballot initiative and pushing for a failed proposal in Congress to require background checks for gun show sales -- a measure Democrats are still pushing today.
"It does not make sense for us at this point in our history to turn our backs on the reality that there are too many guns and too many children have access to those guns -- and we have to act to prevent that," Clinton said in a 1999 speech to the National Education Association after the Columbine massacre .
Once she entered the Senate in 2001, Clinton backed a series of gun control measures.
She backed Democratic bills to require the registration of all new guns, requiring photo IDs and safety lessons for all new gun owners and increasing the minimum buying age for handguns from 18 to 21.
2008 campaign: A shift in tone
Once Clinton launched her 2008 Democratic presidential campaign, though, she backed away from some of those stances -- including her previous support for national licensing and registration of handguns.
"What might work in New York City is certainly not going to work in Montana. So, for the federal government to be having any kind of blanket rules that they're going to try to impose, I think doesn't make sense," Clinton said at an April debate.
She declined to support Washington, D.C.'s ban on handguns.
"What I support is sensible regulation that is consistent with the constitutional right to own and bear arm. I think a total ban, with no exceptions under any circumstances, might be found by the court not to be (constitutional). But I don't know the facts," she said.
The best evidence of Clinton's shift in tone, though, came later in April in Indiana, after Obama had been recorded saying that people in rural America "cling to guns or religion."
In Valparaiso, Indiana
, Clinton discussed her own experience with guns.
"You know, my dad took me out behind the cottage that my grandfather built on a little lake called Lake Winola outside of Scranton and taught me how to shoot when I was a little girl," she said.
"You know, some people now continue to teach their children and their grandchildren," she said. "It's part of culture. It's part of a way of life. People enjoy hunting and shooting because it's an important part of who they are. Not because they are bitter."
2016 campaign: Gun control leader
Again a candidate for president, Clinton has made her advocacy for new restrictions a focal point of her 2016 campaign.
She has called for a ban on the sale of assault weapons, as well as the closure of the "Charleston loophole" -- a reference to a law that allowed the Charleston church shooter to obtain his firearms. Closing that loophole would mean extending the window for FBI background checks to take place on gun purchases.
In a major primary campaign wedge issue against Vermont Sen. Bernie Sanders, Clinton called for the reversal of a law that protects gun manufacturers from liability in lawsuits over shootings. She's also proposed taking executive action to end the loopholes that allow gun show sales and internet sales to escape background checks.
As Trump has increasingly focused on the potential that Clinton would appoint justices to the Supreme Court who would strip away gun rights, Clinton has insisted that while she believes in a constitutionally protected right to own a gun, she supports "reasonable" restrictions on those rights.
"I think what the court said about there being an individual right is in line with constitutional thinking," Clinton said about two weeks ago on "Fox News Sunday," affirming individual gun rights.
"I'm not looking to repeal the Second Amendment. I'm not looking to take people's guns away," she said. "But I am looking for more support for the reasonable efforts that need to be undertaken to keep guns out of the wrong hands."