Joe Biden officially declared Democratic Party nominee for president

Milwaukee: Joe Biden has been officially declared the Democratic Party's presidential nominee during a convention broadcast in which a security guard he befriended in an elevator played a surprise starring role alongside two former presidents and Biden's wife Jill.

The second night of the Democratic National Convention featured endorsements of Biden from former presidents Bill Clinton and Jimmy Carter, as well as former Republican secretary of state Colin Powell.

Joe Biden and wife Jill celebrate officially receiving the Democratic Party's nomination.Credit: DNC

Clinton used his speech on Tuesday night (Wednesday AEST) to blast Donald Trump's record as President, discarding the tradition that past presidents avoid strongly criticising their successors.

"If you want a president who defines the job as spending hours a day watching TV and zapping people on social media, he’s your man," Clinton said of Trump.

"At a time like this, the Oval Office should be a command centre. Instead, it’s a storm centre. There’s only chaos. Just one thing never changes — his determination to deny responsibility and shift the blame."

The 95-year-old Carter, who has been in poor health, said: "Joe has the experience, character, and decency to bring us together and restore America’s greatness ... Joe Biden must be our next president."

The second night of the Democratic Convention lacked the fireworks of Michelle Obama's speech on night one, but was impressively executed at a technical level.

While night one was mostly focussed on attacking Trump, the second emphasised Biden's strengths as a candidate: his personal empathy and his lengthy experience in foreign policy and national security.

Although Biden is well known from his decades in the Senate and as Barack Obama's vice-president, he is still hazily-defined for many voters.

The Biden campaign selected a New York Times security guard named Jacquelyn as the first person to enter Biden’s name for the party's nomination — a decision intended to highlight his ability to connect with ordinary people.

Biden met Jacquelyn while visiting the newspaper for a meeting with its editorial board at the start of this year, and a video of the pair's meeting went viral.

"I take powerful people up on my elevator all the time," Jacquelyn said during the convention. "When they get off, they go to their important meetings. Me, I just head back to the lobby. But in the short time I spent with Joe Biden, I could tell he really saw me. That he actually cared. That my life meant something to him."

Biden's wife Jill, a teacher, gave the night's keynote speech in a video filmed in an empty school room, highlighting the uncertainty many Americans feel about their children's return to school during a pandemic.

Jill Biden recounted falling in love with Biden after the death of his first wife and young daughter in a car crash in 1972. She also told how Biden returned to work as vice-president four days after the funeral of son Beau, who died of brain cancer in 2015.

Jill Biden says her husband's experience recovering from personal tragedy would help him lead the nation through the pandemic and the mass unemployment it has caused.Credit: Bloomberg

She said her husband's experience recovering from personal tragedy would help him lead the nation through the pandemic and the mass unemployment it has caused.

"How do you make a broken family whole?" Jill Biden asked. "The same way you make a nation whole. With love and understanding, and with small acts of kindness. With bravery. With unwavering faith."

Biden was declared the party's nominee after an unusual "roll call" featuring video contributions from Democrats in all 50 of America's states, as well as Washington D.C and Puerto Rico. The roll call would usually take place on the convention floor, but this year's event is being held virtually because of the coronavirus pandemic.

Former US secretary of state Colin Powell endorses Joe Biden during the virtual Democratic National Convention.Credit: Bloomberg

Colin Powell, who served as George W Bush's secretary of state, said Biden would "be a president we will all be proud to salute.

"With Joe Biden in the White House, you will never doubt that he will stand with our friends and stand up to our adversaries — never the other way around.

"He will trust our diplomats and our intelligence community, not the flattery of dictators and despots."

Even though Powell previously endorsed Barack Obama and Hillary Clinton, the Biden campaign hopes his endorsement will help enhance Biden's appeal with Republican and independent voters.

A video documentary also highlighted Biden's decades-long friendship with the late 2008 Republican nominee John McCain. The video featured quotes from McCain's wife Cindy, but she did not explicitly endorse him.

The previous night's broadcast featured an endorsement from former Republican governor John Kasich.

Rising progressive star Alexandria Ocasio-Cortez appeared briefly, but only to nominate Bernie Sanders for the party nomination in a procedural portion of the broadcast. She later posted a clarification on Twitter, explaining the protocol and backing Biden.