Obama has actually done nothing to alleviate the concerns of centrist and center-right voters, while at the same time appearing to go out of his way to stick a thumb in the eye of his liberal base.
Obama is similar to Bill Clinton. He's driven by raw ambition. He'll adopt and discard "principles" (among other things) as long as the effort leads to the White House. I doubt the majority of the American voters will cast the ballot for such a phoney during a world war.