Houston (AFP) – Joe Biden notched up startling wins over leftist rival Bernie Sanders in the Democrats’ Super Tuesday contest to challenge President Donald Trump, with a torrent of projected victories showing his surprising muscle after what had appeared to be a failing campaign.But despite early disappointments Sanders was still expected to rack up large numbers of delegates in by far the biggest states of the night, Texas and California, where polls were due to close at 0400 GMT.With delegates in 14 states up for grabs, Biden was projected to win in Virginia, North Carolina, Alabama, Oklahom…