PITTSBURGH - Hillary Clinton fired back at Donald Trump on Tuesday, saying the presumptive Republican nominee is offering voters little more than "outright lies," ''bizarre rants" and "nonsensical" words in the wake of the Orlando massacre.

"He is the Republican nominee for president," she said, almost incredulously. "We don't need conspiracy theories and pathological self-congratulations. We need leadership and concrete plans because we are facing a brutal enemy."

Clinton called on "responsible Republicans" to denounce Trump's accusations about President Barack Obama's loyalties, noting that "history will remember what we do in this moment." She went after Trump for criticizing Democrats refusal to call the attacks "radical Islamic extremism."

"Is Donald Trump suggesting that there are magic words that once uttered will stop terrorists from coming after us?" she asked union members at a campaign event in Pittsburgh, echoing comments being delivered by Obama in Washington at virtually the same moment.

Her nearly point-by-point rebuttal to Trump's speech a day earlier underscores the balancing act Clinton faces, as she tries to both take on Trump's bombastic attacks and while maintaining focus on the high-minded policy prescriptions that have been the backbone of her campaign.

Clinton's campaign believes her sober view of national security could win over independents and Republicans disturbed by Trump's inexperience and provocative rhetoric.

They're trying to exasperate the divides within the GOP by presenting Clinton as a safe choice for the party's more moderate voters.

On Monday, Trump focused much of his response to the Orlando shooting on Clinton, accusing her of backing immigration policies that would spur a wave of extremism on U.S. soil. Earlier that day, he suggested that Obama was sympathetic to Islamic extremists, telling Fox News: "People cannot, they cannot believe that President Obama is acting the way he acts and can't even mention the words 'radical Islamic terrorism.' There's something going on."

On Tuesday, Clinton lashed back, calling his comments "shameful" and "disrespectful."

"It is yet more evidence that he is temperamentally unfit and totally unqualified to be commander in chief," she said.

On Monday, the presumptive Democratic nominee delivered a speech in which she offered a policy-laden response to the shooting, stressing the need for national unity and a coordinated approach to "lone wolf" attacks. She never mentioning Trump's name - though she alluded to some of his campaign slogans.

Less than twenty-four hours later, Clinton set aside that kind of traditional restraint, even as she called for national unity.

Trump, she said, "needs to distract us from the fact that he has nothing substantive to say."