A party that loses a House seat can win it back two years later, as Republicans just proved. But a party that loses a legislative fight against a middle-class health care entitlement never restores the old order. Pretty soon, Republicans will be claiming the program as their own. Indeed, one of their favorite arguments against this year’s health care bill was that it would cut funding for Medicare. Now they’re pledging to rescind those cuts. In 30 years, they’ll be accusing Democrats of defunding Obamacare.