(Paul Moseley)

But President Rick Perry couldn’t unilaterally unwind the core coverage components in the bill: The Medicaid expansion and insurance subsidies are law, and the president could no more choose to ignore that statute then he could choose to stop sending out Social Security checks. That would mean a broken system that’s wasting a lot of money. So the question is, what would happen next?

In a world where President Rick Perry is joined by Majority Leader Mitch McConnell and Speaker John Boehner — a world that Nate Silver, for one, thinks is possible — this conversation is moot: The law’s regulations and mandates could be waived and its Medicaid expansion and insurance subsidies could be repealed through the budget reconciliation process.

The more interesting question is what happens if President Rick Perry finds himself facing Speaker Nancy Pelosi, or Majority Leader Harry Reid, or both. The plausible outcomes in that scenario are “nothing” or “Republicans and Democrats agree on some set of changes to the law that both sides can live with.” That sort of compromise doesn’t seem so likely with a President Perry, but it seems entirely plausible with a President Mitt Romney.