US President-elect Joe Biden delivered a forceful rebuke on Monday to President Donald Trump's attacks on the legitimacy of his victory, hours after winning the state-by-state Electoral College vote that officially determines the US presidency.<br /><br />California, the most-populous US state, put Biden over the 270 votes needed to win the Electoral College when its 55 electors unanimously cast ballots for him and his running mate, Kamala Harris. <br /><br />Biden and Harris will be sworn in on January 20.
