On Tuesday, the Senate—with the late, dramatic arrival of Sen. John McCain, who cast a deciding vote—opened the floor to Obamacare repeal. A procedural vote, it was the remarkable capstone of an unprecedented effort to pass major legislation without hearings, independent testimony, or public input. What makes it potentially history-making, and not just noteworthy, is that it also marks a milestone for our country: the beginning of what is, thus far, one of the most aggressive attempts at revoking a broad guarantee of the American welfare state.