Defiant Biden throws down the gauntlet to Democrats

US President Joe Biden and First lady Jill Biden walk to the White House in Washington.

President Joe Biden has insisted again that he will not quit the US election race, as the White House denied he has Parkinson's disease following a disastrous debate performance.The 81-year-old dared Democratic critics to either challenge him at next month's party convention in Chicago or back him against Donald Trump in November's vote.The president lashed...