Report: A Republican Supreme Court victory on PPACA could backfire in 2016 swing states

In Pennsylvania—a state that Republicans have unsuccessfully tried to put in play for a generation, where Sen. Pat Toomey faces a reelection fight—nearly 349,000 residents would lose a monthly average of $227 in premium tax credits and swallow a 177 percent premium hike.

In Indiana, which went blue in 2008 and back to red in 2012, nearly 160,000 people would lose an average of $320 in monthly tax credits and face a 271 percent premium hike.

In North Carolina, which also flipped from blue in 2008 to red in 2012, more than 458,000 residents would lose a monthly average of $316 in tax credits and face a 336 percent premium hike.

Meanwhile, PPACA beneficiaries in states like California and New York, which set up their own exchanges, would be untouched by the ruling.

Congressional response?

So far, congressional Republicans have not coalesced around a contingency plan as competing factions of the party are divided on what to do if the justices agree that the subsidies are restricted to people buying on state exchanges.

"We could be looking at a moment of chaos," Johnson told Bloomberg last month. He has offered a bill to continue the subsidies through August 2017.

Republicans like Johnson worry that failing to respond would arm Democrats in 2016 with horror stories of people who lost their health coverage and bring about attack ads claiming Republicans took it away from them. Tuesday in Orlando, Walker said Congress must act if the subsidies are erased: "States didn't create this problem, the federal government did. And they should fix it."

House Majority Leader Kevin McCarthy of California said this week Republicans won't release their response legislation before of the court's ruling, which is expected this month. Party leaders had wanted a contingency plan in place ahead of time.

On Tuesday, Wyoming Sen. John Barrasso, the fourth-ranking Senate Republican, met with House Republicans to emphasize that the party needs to be ready to respond quickly with a plan if the subsidies are erased, his aide said.

But, the Barrasso aide added, he did not say Republicans would release a plan prior to the ruling in the case, called King vs. Burwell. It's unclear how the justices will rule.