Susan Rice, a former UN ambassador and national security advisor under President Barack Obama, has skyrocketed up the odds to be Joe Biden’s running mate. Rice is +650 in odds posted Sunday at 888sports' UK-facing betting site, the third choice just behind Florida Rep. Val Demings, who is at +550. California Sen. Kamala Harris remains the favorite at -134. That marks Harris' best odds ever. Ten days ago, Rice was +2500 to be Biden’s running mate before reports emerged that she was one of six women seen as serious contenders and on the short list.