Biden, Sanders push for votes in Michigan, key US primary

US Democratic presidential candidate Joe Biden, surging in the polls and with several weighty endorsements in his pocket, and rival Bernie Sanders hit the campaign trail in Michigan on Monday on the eve of a primary vote in the key battleground state.Biden, 77, was joined at an event in Flint, Michigan, by Cory Booker just hours after the New Jersey senator and one-time presidential hopeful announced he was throwing his support behind the former vice president."This could be the turning point no