Obama on campaign trail for Clinton as Melania Trump bids to boost husband's bid

US president Barack Obama and Melania Trump have both joined the campaign trail as Hillary Clinton and Donald Trump try to drum up support with less than a week to go until Election Day.

Mr Trump warned that a cloud of investigation would follow Mrs Clinton into the White House, evoking the bitter impeachment battle of the 1990s in a closing campaign argument meant to bring wayward Republicans home.