Don't get me wrong. President Obama has committed partisans and interest groups (like the unions) that will fight hard to get him re-elected. But he has failed to engender the kind of personal liking and loyalty that made such a difference to Bill Clinton when he was embattled . . . again, kind of like Jimmy Carter did.
Liking and loyalty is the mother's milk of a successful politician. Barack Obama rose so quickly that no one really had a chance to figure out if they liked him or not. That has changed, and although it doesn't doom his chances of re-election, it does nothing to help them.
Regular Americans have caught on that President Obama doesn't like them much.