Former first lady Michelle Obama told the Democratic National Convention on Monday that Joseph R. Biden is a battle-tested man of faith who fought alongside her husband for eight years and can be trusted to shepherd the country through tough times.
Sen. Bernard Sanders, reprising his role as runner-up for the Democrats’ presidential nomination, delivered a passionate plea to his party’s left wing not to let squabbles over Mr. Biden’s liberal purity prevent them from ousting President Trump.
Former Ohio Gov. John Kasich led a parade of fellow Republicans to the convention to deliver the message that they won’t let party lines derail the chance to stop Mr. Trump.
“I’m a lifelong Republican,” he said, according to speech excerpts, “but that attachment holds second place to my responsibilities to my country. That’s why I’ve chosen to appear at this convention.
“In normal times, something like this would probably never happen, but these are not normal times.”
It was a fitting summation of the first national political convention to be held during the COVID-19 pandemic.
Mrs. Obama’s remarks were taped via video. Others spoke by livestream, with musical performances spliced in to create a feeling akin to a telethon.
The changes were dictated by fear of spreading the coronavirus, which has upended Americans’ lives, rewritten the rules of the economy and reshaped the political playing field.
The coronavirus and Mr. Trump’s uneven response to it were dominant themes and served as a metaphor for the president’s overall time in office.
“Only a strong body can fight off the virus, and America’s divisions weakened it. Donald Trump didn’t create the initial division. The division created Trump; he only made it worse,” New York Gov. Andrew Cuomo said in a preview of his remarks.
Polls show Mr. Biden leading Mr. Trump, thanks in no small part to more than 170,000 U.S. deaths attributed to COVID-19.
Democrats entered their convention cautiously optimistic but fearful of a repeat of 2016, when their nominee, Hillary Clinton, led in polling yet lost the election.
The theme Monday was “We the People,” suggesting Mr. Biden’s ability to unify Republicans and Democrats, including those from Mr. Sanders’ more liberal wing of the party.
“The future of our democracy is at stake. The future of our economy is at stake. The future of our planet is at stake,” Mr. Sanders said. “My friends, the price of failure is just too great to imagine.”
Mrs. Obama, meanwhile, aimed her remarks at her husband’s legions of fans.
“I know Joe. He is a profoundly decent man guided by faith,” Mrs. Obama said. “He was a terrific vice president. He knows what it takes to rescue an economy, beat back a pandemic and lead our country — and he listens.”
Other speakers included actress Eva Longoria, Rep. James E. Clyburn of South Carolina, Gov. Gretchen Whitmer of Michigan, Sen. Doug Jones of Alabama, Sen. Catherine Cortez Masto of Nevada and Sen. Amy Klobuchar of Minnesota.
Joining Mr. Kasich as Republicans backing Mr. Biden were former New Jersey Gov. Christine Todd Whitman, who served in George W. Bush’s administration; former Hewlett Packard Enterprise CEO Meg Whitman, who once ran as the Republican nominee for California governor; and former Rep. Susan Molinari, who delivered the keynote address at the 1996 Republican National Convention, where Bob Dole accepted his party’s nomination.
Trump campaign spokesman Tim Murtaugh said it is a “joke” to claim Mr. Biden is making inroads with Republicans.
He said Mr. Biden is outside the mainstream, proven by his work with Mr. Sanders to write the party’s platform and his choice of liberal Sen. Kamala D. Harris of California to be his running mate.
“The radical leftist takeover of Joe Biden is complete,” Mr. Murtaugh said.
“President Trump has inspired unprecedented support among Republicans and leads a united party,” he said. “Joe Biden has enough trouble generating enthusiasm in his own party, so he should worry about that before anything else.”
Mr. Trump himself slammed Mr. Kasich, saying “people don’t like him, people don’t trust him.”
“He was a loser as a Republican, and he’ll be a loser as a Democrat,” he told reporters on Air Force One.
Giving plum speaking slots to Republicans didn’t sit well with some on the far left, who said their champions and vision were getting short shrift.
The virtual nature of the campaign, however, is expected to shield Mr. Biden from the sorts of large-scale protests and rallies that have characterized past conventions, forcing his critics to find other avenues to extol their complaints.
Former Sanders campaign adviser Chuck Rocha said it is difficult to believe that Mr. Kasich was given more time to address the convention than Rep. Alexandria Ocasio-Cortez of New York, who was given one minute to introduce Mr. Sanders.
“If AOC only gets a minute, how does somebody else break into the hierarchy?” Mr. Rocha said on the SiriusXM POTUS channel. “We have to change the way that we do this to welcome more people and give them a bigger platform.”
Democratic National Committee Chairman Tom Perez said he disagrees with Mr. Kasich on a number of topics, such as union rights and women’s health issues, but he added that it is important for his voice to be heard.
“People will hear from leaders with whom they have disagreed,” he said at a Washington Post event. “But what we are all in agreement on this week and throughout is that Joe Biden is the person for the job.”
Rep. Cedrick Richmond of Louisiana, the Biden campaign co-chair, said the goal of the convention is to show the full breadth of Mr. Biden’s support.
“There are a bunch of people out there — silent Biden voters, Republicans that want to vote for Biden or that will be voting for Biden — and it is important to let them know that they are not alone and it is OK that there are Republican leaders that are voting for Biden-Harris,” Mr. Richmond said. “Just as any segment of the population that you have support from, you make sure that support is known.”
Patrick Murray, director of the Monmouth University Polling Institute, said there are Biden and Trump supporters who are not “broadcasting their current support to neighbors and friends for various reasons.”
“We have evidence that many people have cut down on talking about politics in public, but there is no evidence that the polls are missing or miscounting these voters on either side,” he said.
Mr. Murray’s polls have shown Mr. Biden has a slight edge in crossover support.
Charles Franklin, director of the Marquette Law School Poll, said it is no accident that Democrats are trying to steal Mr. Trump’s silent majority argument.
Mr. Franklin said the message has helped Mr. Trump raise doubts about the national and battleground state polls showing him running behind Mr. Biden.
Mr. Franklin said his polls also show Democrats have a slight party loyalty edge in Wisconsin at the moment: Roughly 4% of likely Republican voters plan to back Mr. Biden, and 1.5% of Democrats plan to vote for Mr. Trump.
“My takeaway from all of this is that there is a small set of Republicans that are supporting Biden and that is a bit more than double the number of Democrats who are crossing over to vote for Trump,” he said. “But these are the ones revealing themselves, and so by definition, we don’t know what the answers of the people who don’t agree to be interviewed would be.”
• David Sherfinski and Stephen Dinan contributed to this report.