835 days and counting. the next presidential election might seem a long ways off, but the buzz surrounding which democrats might run against trump is building. cnn has a new definitive power list of ten possible challengers. >> let's run through. let's show the first. we are going least likely to be nominee to most likely. i want to pick here eric holder, the former attorney general, not the most likely candidate at the start of 2017 but he has been to early primary states and has talked about running against trump and he is someone who can carry that obama legacy. anoth you'll see bernie sanders which might be a little odd to some folks. why is bernie sanders who was the runner up to hillary