California billionaire Tom Steyer spent $47 million in three months on presidential bid

California billionaire Tom Steyer spent $47 million during the first three months of his presidential bid - a jaw-dropping sum that places him on track to join the biggest self-funding political candidates in American history.

Joe Biden, one of the front-runners in the Democratic presidential primary, finds himself in a precarious financial position, having spent ($17.7 million) more than he raised ($15.7 million), according to campaign finance disclosure forms released late Tuesday.