Sanders back to the drawing board after Joe Biden's 'Super Tuesday'

His front-runner status slipping, Bernie Sanders refocused his Democratic presidential campaign on surging rival Joe Biden on Wednesday as the Vermont senator's allies grappled with the fallout from a Super Tuesday stumble that raised internal concerns about the direction of his White House bid.

Sanders targeted Biden's record on trade, Social Security and fundraising just hours after billionaire Mike Bloomberg suspended his campaign and Elizabeth Warren confirmed she was privately reassessing her future in the race.

The dramatic shifts signaled that the Democrats' once-crowded nomination fight had effectively come down to a two-man race for the right to face President Donald Trump