The rivals dueled in a flurry of television interviews Monday, battling for political advantage in the aftermath of a rampage at an LGBT nightclub in Orlando that left 49 people dead despite the risk of being seen as exploiting one of the most traumatic days in the nation's recent history.
Trump seized on the chance to bolster his campaign after several weeks of self-inflicted wounds. In an interview with CNN's "New Day," he warned there were "thousands of people" in the United States with "hate in their heart" and complained those in Muslim communities had not reported "mad" men like the Orlando shooter to the police or the FBI.
The presumptive Republican presidential nominee dismissed calls for new gun laws to stop terrorists buying weapons, saying: "If you had guns on the other side, you wouldn't have had the tragedy you had," and blasted Clinton and President Barack Obama, arguing they had facilitated such tragedies.
"We have very weak leadership," he said. "Hillary will be weaker than Obama if she got in."
In an interview on Fox News, Trump seemed to suggest that Obama, who labeled the attack an "act of terror," was somehow complicit in the massacre.
"We're led by a man that either is not tough, not smart, or he's got something else in mind," Trump said. "People can't believe it ... They can't believe that President Obama is acting the ways he acts and can't ... mention the words radical Islamic terrorism. There's something going on. It's inconceivable."
Clinton, the presumptive Democratic nominee, framed Trump's response as proof that he was temperamentally unsuited to lead the nation.
In an interview on "New Day," she warned Trump's rhetoric was "quite dangerous for our country," and dismissed his accusations that she was frightened to use the words "radical Islamic terrorism" -- a frequent Republican charge.
"It matters what we do more than what we say and it mattered we got bin Laden, not what name we called him," Clinton said.
"I have clearly said ... whether you call it radical Jihadism or radical Islamism, I'm happy to say either. I think they mean the same thing," said Clinton, who also called for new restrictions to make it harder for home-grown terrorists to get guns.
On CBS' "This Morning," Clinton said Trump was obsessed with name calling and faulted his response to the attacks, saying: "We also have to get this out of partisanship -- it's a moment for statesmanship."
Trump's tough talk was similar to the rhetoric he adopted after attacks in Paris and San Bernardino, California. His proposal to temporarily ban Muslims from entering the U.S. in the aftermath of the San Bernardino attacks, for instance, resonated deeply with the GOP primary electorate.
Seeking to steal the momentum from the Clinton campaign, Trump ditched plans to make a speech Monday castigating the former first lady and husband Bill Clinton. Instead, he will deliver a major address in New Hampshire on the terrorist attack, immigration and national security.
The Clinton campaign quickly moved to head off the Trump offensive, making clear that the she would soon lay out her own ideas for combating the evolving threat from home-grown terrorism and dismissed Trump's bid to use the attack to bolster his political prospects.
"This act of terror is the largest mass shooting in American history and a tragedy that requires a serious response," said Clinton communications director Jennifer Palmieri in a statement.
"In contrast, Donald Trump put out political attacks, weak platitudes and self-congratulations," Palmieri said. "Trump has offered no real plans to keep our nation safe and no outreach to the Americans targeted, just insults and attacks. In times of crisis more than ever, Americans are looking for leadership and deserve better."
At the same time, the Clinton camp absorbed a political blow in canceling a planned first joint campaign appearance with Obama on Wednesday in Wisconsin.
The political maneuvering comes after several weeks of bad news for Trump, and his swift mobilization in the aftermath of the horrific attack recalled his nimble topic-shifting on fast-developing dramas during his successful Republican primary campaign. Until now, he has proved less adept at quick subject changes under the increased scrutiny of the general election fight.
The real estate magnate has been under fire from Clinton for several weeks over his personality, temperament, conduct towards women, perceived lack of foreign policy knowledge and allegations of impropriety in his business history.
He has simultaneously faced condemnation from senior members of his own party over missteps, including his comments that a U.S.-born judge with Mexican ancestry is biased against him in a civil suit focusing on Trump University.
But the resurgent fear of terrorism, which will likely dominate the news agenda for days, provides Trump politically safer ground.
Tough talk on terror is a cause behind which many Republicans, even those skeptical of Trump, can unite. And the shooting offers at least the prospect of reversing Obama's rising approval ratings, which are currently above 50% and therefore helpful to Clinton.