Speaking from the White House South Lawn despite criticism he was using the executive residence as a political prop, Trump portrayed Biden, a career politician with a long record as a moderate, as a far-left extremist who would usher in a lawless, dangerous America.
"This election will decide whether we protect law-abiding Americans, or whether we give free rein to violent anarchic agitators and criminals who threaten our citizens," Trump said on the fourth and final night of the Republican National Convention in a rambling speech that lasted more than an hour.
"No one will be safe in Biden's America."
Despite the pandemic, Trump delivered his remarks in front of more than 1,000 people, standing in front of dozens of American flags and basking in chants of "Four more years!" and "U.S.A.!"
Though an incumbent, Trump remains a self-styled outsider, an approach that won him the White House, his first elected office, in 2016 on a promise to end the crime and violence he said was afflicting the country.
After days of civil unrest and violence in Kenosha, Wisconsin, where on Sunday police shot a Black man, Jacob Blake, in the back, Republicans on Thursday sought to turn the chaos to their advantage by claiming Biden would "defund the police." Biden has rejected that position.
In trying to paint Biden as a tool of the "radical left," Trump also distorted the Democrat's policy positions on a host of other issues, including immigration, guns, law enforcement, abortion and energy production.
As the night unfolded, Biden struck back on Twitter, writing, "When Donald Trump says tonight you won't be safe in Joe Biden's America, look around and ask yourself: How safe do you feel in Donald Trump's America?"
The made-for-television scene - befitting the first reality TV host to serve as president - stood in marked contrast to Biden's acceptance speech last week, which was broadcast live from a largely empty arena in a nod to the disease.
The crowd, seated in white chairs inches apart, showed little evidence of social distancing or face masks despite health experts' recommendations.
The coronavirus prompted both political parties to scale back their conventions and make events mostly virtual. The Trump campaign said it had taken appropriate health precautions.
In a reminder of the country's divisions, attendees could hear anti-Trump protesters at nearby Black Lives Matter Plaza as he spoke.
MORE THAN 180,000 DEATHS
More than 180,000 people have died in the United States from the coronavirus - more than any other country, according to a Reuters tally - amid a fresh wave of protests over the latest high-profile police shooting of a Black American.
In Kenosha, relative calm returned after three nights of civil strife ending on Tuesday, including arson, vandalism and deadly shootings.
Trump, a former New York real estate developer, is seeking to turn around a re-election campaign that has been largely overshadowed by a health crisis that has put millions of Americans out of work.
In his speech on Thursday, Trump repeated his assertion that China is to blame for the pandemic and promised to rebuild what Republicans have called the "greatest economy" in history. But opinion polls have shown most Americans are disappointed in his response to the coronavirus, which he played down for weeks.
While his approval rating among Republican voters remains high, dissent is mounting within the party. In three open letters being published on Thursday and Friday, Biden won endorsements from more than 160 people who worked for Republican former President George W. Bush or for past Republican presidential candidates Mitt Romney and John McCain, the New York Times and Politico reported.
Earlier this week, 27 former Republican lawmakers endorsed Biden while the Lincoln Project, among the most prominent Republican-backed groups opposing Trump, said a former Republican Party head had joined it as a senior adviser.
Thursday's program aimed to counterbalance those defections, featuring a video showcasing former Democratic voters who say they now support Trump and remarks from U.S. Representative Jeff Van Drew, who abandoned the Democratic Party to join the Republicans after voting against Trump's impeachment this year.
"Joe Biden is being told what to do by the radicals running my former party, the same radicals trying to install him as their puppet president," he said.
The program also included several emotional appeals, including from the parents of Kayla Mueller, an aid worker who died after being held captive for months by Islamic State militants in Syria. The Mueller parents said they blamed the Obama administration for failing to rescue Mueller.
Trump kicked off the week on Monday by accusing Democrats of seeking to steal the election by advocating for mail-in voting. His previous high-profile speeches have also emphasised grim themes, including his inaugural address in January 2017 that described "American carnage."
