In his first major election address against his Democratic rival, the real-estate mogul labelled Mrs Clinton a “world class liar” and lambasted her long political record.
“No Secretary of State has been more wrong, more often, and in more places than Hillary Clinton,” he said. “Her decisions spread death, destruction and terrorism everywhere she touched.”
In claims that foreshadowed the likely tone of the coming national race, the Republican presidential candidate boldly pinned the sweeping chaos, violence and complex politics of the Arab Spring directly on his opponent.
“In just four years, Secretary Clinton managed to almost single-handedly destabilise the entire Middle East,” he said. Though Mrs Clinton has not presided over any US led ground war, he claimed that her foreign policy had cost “America thousands of lives”.
Her support for the rebel opposition in Syria and the war in Libya had “unleashed Isil across the world”, he said.
That, is going to prove a challenge. Last week a Washington Post-ABC News poll found that some 70 percent of Americans have an unfavorable view of Mr Trump, including a 56 percent majority who feel this way “strongly.
Mr Trump’s speech came after a bad week for the his campaign, with polls showing him a full ten points behind Mrs Clinton.
On Tuesday Mrs Clinton delivered a policy address on the economy in which she said a Trump presidency, whom she called the “king of debt” would throw the country back into recession.
She derided her rival’s business record, describing his fortune as being founded on his repeatedly “stiffing” his employees.
“Donald Trump’s ideas about the economy and the world will cause millions of Americans to lose their jobs,” she told her audience in Ohio, a state at the heart of America’s industrial rust belt.
Mr Trump’s fundraising totals for May – a mere $3.1 million – also left him tens of millions of dollars behind the Clinton campaign machine.
In response Mr Trump this week fired Corey Lewandowski, who had been overseeing the campaign’s fundraising arm.
The speech was the opening gambit for what his aides have said is a renewed, more professional, presidential campaign.