SCOTTSDALE, Ariz. — Republicans are planning to use the troubled health law against Democrats in next year’s midterm elections, but the Affordable Care Act is increasingly dividing their party, too.

At the annual meeting here of the nation’s Republican governors, the ones who are eyeing presidential runs in 2016 say they oppose the health care law. But there is sharp disagreement among those who have helped carry out the law and those who remain entrenched in their opposition.

These early divisions reveal not only the difficult calculations of ambitious Republican politicians as they look to the next presidential campaign, but also the complexities of being a governor rather than a lawmaker at a time when the party’s base is hostile to those who cooperate with Democrats.

The governors who refused the Medicaid expansion money that is part of the health care law — believing they had found a wedge issue — are already boasting about it.