Joe Biden launches 2020 Presidential campaign

Former US Vice President Joe Biden on Thursday announced his third bid for the Democratic nomination to run for President in a video in which he criticised President Trump and stated that "everything that has made America America, is at stake".

Biden has entered a crowded Democrat field of 20 candidates by launching his campaign and came out of the blocks swinging as he railed against Trump's often derided assertion that there had been "very fine people on both sides" at the deadly Charlottesville white nationalist riots of August 2017.

"With those words, the President of the United States assigned a moral equivalence between those spreading hate and those with the courage to stand against it. I believe history will look back on four years of this president and all he embraces as an aberrant moment in time. But if we give Donald Trump eight years in the White House, he will forever and fundamentally alter the character of this nation, who we are, and I cannot stand by and watch that happen," said Biden.

Biden, who served as deputy Commander in Chief under President Obama and ran unsuccessfully for the nomination in 1988 and 2008, is the most popular option according to a Morning Consult/Politico poll that showed 30% of Democratic voters supporting him, ahead of Bernie Sanders in second place on 24%.

The poll also showed Biden, who would be America's oldest ever President if successfully elected, beating Trump in a head-to-head with a lead of 42% to 34% as he proved more popular among women, millennials and independents.

Seen as a centrist with strong union support, Biden may have a better shot than more progressive Democratic candidates at winning over the working-class white voters in the Rust Belt who snubbed Hillary Clinton in the 2016 Presidential Election.

However, his competitors have had something of a head start as Biden's decision to throw his hat into the ring has come later than some expected, with the former Vice President having faced allegations of inappropriate behaviour at political events where he hugged and kissed strangers in the crowd.

The former Delaware Senator has since apologised, acknowledging that the standards for personal behaviour have evolved in the wake of the #MeToo movement.