This is the statement she needs to make. I doubt she'll offer it on her own, so Obama's people should push that question into the media, to be asked of her:

"Senator Clinton... Given the similarity between your positions and the gaping disparity between democrat and republican positions, wouldn't you tell your supporters that to abstain or to vote for McCain in the General Election would be a betrayal of everything you were campaigning for? Yes or no."

Push back, Obama. Push back. Make her live up to her promise to "campaign her heart out" for you, starting now.