Among voters in the Republican primary, where opposition to abortion motivates a key slice of the electorate, front-runner Mitt Romney is voicing his objections to the rule on grounds that it violates religious liberty. Romney is committed to repealing the whole Obama healthcare law, and the birth control rule along with it, said Amanda Henneberg, a campaign spokeswoman.
"This is a direct attack on religious liberty and will not stand in a Romney presidency," she said.
Garin said Romney's position was unlikely to hurt Obama but risks placing the former Massachusetts governor at odds with the majority of women voters.
"It is reasonable to think that the Catholics who are opposed to birth control are unlikely to be Obama supporters for a whole host of other reasons," Garin said. "But for the significant majority of the electorate, being identified with increasing access to affordable birth control is a clear-cut positive."
The administration pledges to stand behind its decision, with the White House seeing a different moral issue at stake: access to preventive healthcare.