Former US presidents Bill Clinton and Jimmy Carter have argued that Joe Biden has the experience and integrity to restore a pandemic-devastated America, as Democrats formally nominated Biden for president at their national convention.
The convention's second night, under the theme "Leadership Matters," aimed to make the case that Mr Biden would represent a return to normality after the "chaos" of Republican President Donald Trump's administration, as Mr Clinton put it.
"At a time like this, the Oval Office should be a command centre," he said in a prerecorded video. "Instead, it's a storm centre. There's only chaos. Just one thing never changes - his determination to deny responsibility and shift the blame."
With the four-day convention largely virtual due to the coronavirus, delegates from around the country cast votes remotely to confirm Biden as the nominee.
As they did on Monday's opening night, Democrats featured a handful of Republicans who have crossed party lines to praise Biden, 77, over Trump, 74, before the November 3 election.
Jill Biden was set to deliver the headline speech later in the evening, arguing her husband's capacity for empathy will help him offer solace to a battered nation. Former secretary of state John Kerry was also due to speak.
Cindy McCain, widow of Republican senator John McCain, will appear in a video talking about that Arizona Republican's long friendship with Biden. Trump clashed with McCain, who was the Republican nominee for president in 2008, and the president criticised McCain even after his 2018 death.
Republican former secretary of state Colin Powell, who endorsed Mr Biden in June, is one of several national security officials due to speak on the Democrat's behalf.
With the four-day convention largely virtual due to the coronavirus, delegates from around the country will cast votes remotely to confirm Biden as the nominee.
Mr Biden is scheduled to give his acceptance speech on Thursday. His vice-presidential pick, senator Kamala Harris, will headline Wednesday night's program along with Obama.
Without the cheering crowds at the in-person gathering originally planned for Milwaukee, Wisconsin, TV viewership was down from 2016. But an additional 10.2 million people watched on digital platforms, the Biden campaign said, for a total audience of nearly 30 million.
Aiming to draw attention away from Mr Biden, Mr Trump, trailing in opinion polls, held a campaign rally in battleground state Arizona.
Other Democratic speakers on Tuesday included US representative Alexandria Ocasio-Cortez, and Sally Yates, the former acting US attorney-general who clashed with Trump during her brief tenure overseeing the Justice Department.
The Republican National Convention, also largely virtual, takes place next week. Mr Trump will give his acceptance speech at the White House, despite criticism he is politicising the presidential residence.
