The easiest thing for them would have been if Sanders had not been a factor in the primary. Instead, he is absolutely one of the leading candidates, and their preferred guy (Biden) is rapidly fading. Now, they have to decide how to deal with Bernie's potential climb and whether they'll potentially have to endorse someone they don't like or want over Trump. It sounds like many of them are going to be willing to do that, because they amazingly think Bernie is the lesser of 2 "evils."