But can he?
To repeal the law he and the Republicans in the House will need 60 senators in the U.S. Senate to agree with him. That would take a landslide on Nov. 6th within the U.S. Senate and its very, very unlikely to occur.
Mitt Romney says on day one of his administration if elected President he would issue waivers allowing states to opt out of the PPACA. It doesn't work that way however, the states have to request a waiver and those reviews in my Medicaid policy experience can take a year or more. But states under the Supreme Court ruling allows them to opt out of Medicaid expansion and that's where the rubber hits the road.
States can opt out despite the federal government covering 100% of the expansion in the first year. So most of the new cost -- all of it at first; 90 percent eventually -- is being paid by the federal government. Still some states like Wisconsin which resists al lot of federal funding may resist. How do they message that refusal will be interesting but Gov. Walker in Wisconsin has been successful thus far.