Joe Biden has been the effective nominee since Bernie Sanders withdrew in April. How Trump’s health with Coronavirus and its related issues, economic impact, and recent racial violence will decide on the selection factors.
Mr. Biden, who served as Barack Obama’s vice-president, began the primary campaign in faltering style in Iowa and New Hampshire, but then built momentum with a convincing victory in South Carolina.
He then dominated the so-called Super Tuesday contests, taking 10 of the 14 states.
Mr. Biden said: “It was an honor to compete alongside one of the most talented groups of candidates the Democratic party has ever fielded and I am proud to say that we are going into this general election a united party.”
Mr. Biden, 77, secured the nomination officially after seven states and the District of Columbia held presidential primaries on Tuesday.
It is his third bid for the presidency.