"She doesn't have the temperament to be president. She's got bad judgment. She's got horribly bad judgment," Trump said. "If you look at the war in Iraq, if you look at what she did with Libya, which was a total catastrophe."
Clinton as a U.S. senator from New York voted in 2002 to authorize the use of military force in Iraq. And in 2011 as secretary of state under President Barack Obama, Clinton forcefully argued in favor of military intervention to overthrow Libyan dictator Moammar Gadhafi.
Trump, despite his repeated claims to the contrary, also supported both the Iraq War and the U.S.-involved military intervention in Libya those same years.
Asked about his views on the possible war a month before Clinton and 76 other senators voted to authorize military force in Iraq to topple Saddam Hussein, Trump voiced his support.
"Yeah, I guess so," Trump told radio show host Howard Stern in September 2002. "You know, I wish the first time it was done correctly."
Trump has even since conceded his initial support for the war
, but has defended his comments by pointing out that he was a businessman -- and not a politician -- at the time.
And in the early months of the war, Trump -- like most political and military observers at the time -- said the war appeared to be going swimmingly.
"It looks like a tremendous success from a military standpoint," Trump said in a March 2003 interview.
It wasn't until later that year that Trump began expressing skepticism and then outright opposition to the war.
Trump's support for the NATO-led military intervention in Libya was even more stalwart.
"Gaddafi in Libya killing thousands of people, nobody knows how bad it is. And we're sitting around, we have soldiers all over the Middle East, and we're not bringing them in to stop this horrible carnage," Trump said in a February 2011 video he posted online, highlighted in a BuzzFeed report
"We should go in, we should stop this guy, which would be very easy and very quick. We could do it surgically, stop him from doing it, and save these lives. This is absolutely nuts," Trump had said.
One month later, NATO launched military strikes to support rebels fighting Gaddafi in Libya. Today, Libya is a fractured country, with broad swaths of its territory now claimed by ISIS militants.
Still, Trump has used the failures of both military interventions as part of his stump speech as he crisscrosses the country campaigning for president, and particularly now that he has increasingly leaned into Clinton, the likely Democratic nominee, in preparation for the general election.
The billionaire has continued to insist that he was against the Iraq War from the start and has relentlessly attacked Clinton's role in orchestrating the military intervention in Libya.
"If she wins you better get used to it because you'll have nothing but turmoil," Trump said Wednesday.
Beyond attacking Clinton, Trump also rallied his supporters here in Anaheim, California around one of the core tenets of his campaign: immigration.
His rally in this majority Latino city opened with mothers of Americans killed by undocumented immigrants praising Trump and continued with Trump leading the crowd in a chorus of "build that wall."
While he did not back away from any of his immigration proposals, he insisted that his support is growing among Latino voters and noted that he has thousands of Hispanics who work for him: "Hispanics are liking Donald Trump."
"More and more I am seeing Latinos for Trump -- they are with Trump. I have great relationships with the Hispanics," he told the crowd. "We're going to do very well with Hispanics because I am going to create jobs ... We need jobs."
Despite some protester interruptions, Trump's rally Wednesday unfolded calmly in contrast to the chaos that unfolded outside of his event the previous night in Albuquerque, New Mexico.
Police arrested eight people, including one minor, as a few dozen protesters clashed with Trump supporters and police officers, Anaheim Police Department spokesman Sgt. Daron Wyatt told CNN.
Beyond officers physically moving protesters back, Wyatt was not aware of any non lethal munitions being deployed.
Wyatt would not confirm the number of officers deployed but said the department deployed in large numbers to prepare for the potential of violence that has unfolded at Trump rallies across the country.
"We wanted to be prepared. We said from the beginning that we would rather have too many resources than not enough," Wyatt said.