Mr. Romney’s decision, in particular, suggests that candidates who are viewed suspiciously by the state’s religious conservatives may stand little chance there. Mr. Romney, who was once a pro-choice governor and passed a health care plan that served as the inspiration for President Obama’s, has struggled in Iowa for years.

Some of the state’s Republicans had already been wringing their hands about the outsize influence of the state’s religious conservatives.

“If Iowa becomes some extraneous right-wing outpost, you have to question whether it is going to be a good place to vet your presidential candidates,” Doug Gross, a Republican activist from Iowa, told The New York Times this year…

In fact, the Iowa caucuses now seem more likely to become an opportunity for one of the several lesser-known Republican candidates who are trying to cut through the campaign clutter and are counting on their appeal to the conservative Tea Party movement.