Wall Street Journal yesterday wrote that support for Romney is firming up with "likely" GOP voters, including self-described nservatives. He's got 38% vs. 32% for Santorum. Article also says many have been turned off by the ugliness of the campaign.
What this tells me is that 62% of likely GOP voters don't want Romney, and that he can't count on them falling in behind him if and when he gets the nomination.