The battle over the federal deficit hasn’t flipped in favor of the Democrats. The GOP isn’t suddenly at grave risk of losing its House majority.

But after two years of getting pummeled over spending and the size of government, Democrats now appear to have found a political weapon that’s capable of evening out the fight: Medicare.

The popular entitlement program wasn’t the sole issue behind Kathy Hochul’s upset victory in a New York special election Tuesday night, but strategists in both parties say it was an important force. And for the first time since November, the idea that Democrats might have a shot at winning back the House is no longer a laughing matter.