FBI's Comey: from Clinton bugbear to thorn in Trump's side?

Eight months ago, James Comey hampered Hillary Clinton's White House bid with a damning assessment of her email practices.On Monday, the powerful FBI chief lobbed another bombshell into the world of US politics -- this time directed at the sitting president, Donald Trump.In a high-stakes congressional hearing followed live by millions in America and around the world, Comey flatly rejected Trump's explosive claim that he was wiretapped by his predecessor Barack Obama.