Noam Scheiber addresses two probable scenarios, "either a single-digit Romney loss or a single-digit Romney win." He thinks neither result will change much:
Win or lose for Romney, we’ll still be stuck in the same pattern: Romney pulls out victories when he spends a lot of money and when the demographics tilt in his favor (i.e., proportionately fewer conservatives and more affluent people), and loses when he either doesn’t spend enough money or the demographics aren’t sufficiently in his favor. Unfortunately for Romney and the GOP, that’s a hell of a depressing way to win a presidential nomination.
The Dish 