Conservatives have long been uneasy with Romney’s record on healthcare. But as an Obama-Romney matchup becomes increasingly likely, so does the prospect that Republicans won’t be able to aggressively campaign against a law that helped propel their historic wins in 2010 — and hasn’t gotten much more popular since.

“I think as an attack against Obama it’s totally off the table,” Democratic pollster Celinda Lake said…

The Democratic National Committee released a web ad Friday that focuses entirely on the individual mandate and quotes Romney saying, “I like mandates.” It would normally be an unusual move — the mandate is, after all, a central and largely unpopular part of Obama’s healthcare law. But, Lehane said, a chance to accuse Mitt Romney of flip-flopping is more important than the policy itself.

“Any time Romney is talking about health care, he’s losing,” he said.