Obama's chief spokesman and his top campaign strategist both said the administration was searching for ways to allay the concern of Roman Catholics who say the birth control mandate would force them to violate their religious beliefs against contraception. Senate Republican Leader Mitch McConnell said the policy was a "huge mistake" that the administration should reconsider. "And if they don't, Congress will act," McConnell said.

On the campaign trail, GOP presidential hopefuls Mitt Romney and Newt Gingrich heaped new criticism on the president, with Romney accusing Obama of an "assault on religion" and Gingrich calling the rule an "attack on the Catholic Church."

Obama's spokesman defended the decision that prompted the flare-up, even as he raised the prospect of some adjustment. He said women working for church-affiliated employers must be able to get contraception, but he also made clear that the White House wants to accommodate the concerns of the employers who would be required to provide birth control coverage regardless of their religious beliefs.