If Republicans get their way at the Supreme Court this month and wipe out Obamacare premium subsidies for millions of Americans, the ensuing damage to their party in 2016 swing states could be poignant.

A state-by-state analysis by the Kaiser Family Foundation found that about 6.4 million Americans in 34 states that use the federal marketplace would lose a total of $1.7 trillion monthly tax credit dollars—an average of $272 per person—and face a net premium increase of 287 percent.