Joe Biden speaks at a rally in Dorchester, Massachusetts. File /AFP
Former US vice president Joe Biden jumped into the race for the White House on Thursday, becoming the frontrunner in a crowded field challenging Donald Trump in 2020 — and hoping to be the oldest leader in American history.
The party's 76-year-old senior statesman is the most experienced and best recognised Democrat in the running, a popular former VP who has been dominating early polls following months — even years — of campaign planning.
In a tweet accompanied by a three-and-a-half minute video, Biden said giving Trump four more years in power would be extremely dangerous and "fundamentally alter the character of this nation, who we are."
Biden said a deadly 2017 white supremacist rally in Charlottesville, Virginia woke him to the danger Trump posed, recalling that the president famously described "very fine people" on both sides of the clashes.
"And in that moment I knew the threat to this nation was unlike any I had ever seen in my lifetime," Biden said.
The veteran Democrat added that he couldn't sit back while Trump stood to gut America's core values and "everything that made America America."
"That's why today I'm announcing my candidacy for President of the United States," he said.
Trump's response was swift: he insulted Biden on Twitter, his favorite forum for smacking down rivals, casting doubt on his rival's mental capacity.
"Welcome to the race Sleepy Joe. I only hope you have the intelligence, long in doubt, to wage a successful primary campaign," Trump tweeted.
Biden, whose working-class appeal remains intact despite nearly half a century in Washington politics, is seen as a comforting, known quantity for American voters who will be vetting some 20 Democrats now officially in the presidential field.
But recent controversy over his tactile style, particularly with women, could dampen a rollout that he envisioned as the final main entry to the Democratic primary battle.
Even before his official announcement, Biden, who served eight years as Barack Obama's vice president, led most surveys of Democratic voters.
The RealClearPolitics poll aggregate puts him as favorite with 29.3 per cent support, followed by independent Senator Bernie Sanders at 23 per cent.
The record number of candidates means Biden finds himself in a field of unprecedented diversity as he makes his third run for president, following two unsuccessful attempts in 1988 and 2008.
After the death of his son Beau from cancer, Biden opted out of a presidential campaign in 2016.
As he let the suspense over his political plans drag out for months, his broad lead has been whittled down, with newer and notably young faces gaining ground including moderate South Bend, Indiana Mayor Pete Buttigieg, who at 37 is less than half Biden's age.
Top of the polls
Complicating matters, the last weeks of waiting have been clouded by revelations from multiple women accusing Biden of touching them inappropriately or making them feel uncomfortable with his shows of affection.
Biden, an old-school politico who acknowledges he is quick to offer hugs and shoulder rubs as he forges connections with voters, has not outright apologized for his behavior, but he pledged earlier this month to be "more mindful" about society's changing boundaries.
Obama, through a spokesperson and a source close to his thinking, praised Biden but pointedly avoided endorsing him, saying the Democratic field is very diverse and he prefers to "let the candidates make their cases directly to the voters."
Barring unforeseen disaster, Joe Biden will represent the Democratic Party against President Donald Trump this fall, the former vice president's place on the general election ballot cemented by Bernie Sanders' decision to end his campaign.
Since Representative Justin Amash announced he was forming an exploratory committee to pursue the Libertarian nomination for president, there has been plenty of chatter about such a move harming Joe Biden’s chances of defeating President Trump in November. If Amash indeed gets on the ballot in a handful of swing states, he very well could siphon off some voters who otherwise would have opted for Biden. But what’s more certain at this point is that Amash’s decision hurts the former vice president in a different way.
Biden opened the event saying that as long as Donald Trump is president, the security and future of the United States is at risk. With fewer than 100 days before Nevada Democratic party caucuses, Biden is among the front-runners in crowded field of Democratic candidates for president.
Medical sources said more than 20 people were injured, two of them seriously. Witnesses said several homes were damaged as a result of the explosion in the home of an "activist". Police cordoned off the area.
Severe penalties are imposed for non-compliance with international standards to ensure the highest level of quality in testing, says official.
The rocket attack took place late on Friday night, Xinhua news agency quoted the media office of the Iraqi Joint Operations Command as saying in a statement. The Katyusha rockets landed outside the airport, the statement added.