President Obama's gun control agenda was routed in the Senate on Wednesday, and Mr. Obama naturally blamed the National Rifle Association. The truth is that Mr. Obama invited this meltdown by assuming he could exploit the Newtown massacre to ram through a liberal wish-list that wouldn't have stopped the next mass murder.

The day's biggest news was the defeat of the amendment expanding background checks by Senators Pat Toomey (R., Pa.) and Joe Manchin (D., W.Va.). It fell six votes short of the 60 needed to pass, as four Democrats defected: Max Baucus (Mont.), Mark Begich (Alaska), Heidi Heitkamp (N.D.) and Mark Pryor (Ark.).

And that was the liberals' best hope. The President's proposed bans on certain rifles and large ammunition clips didn't even make 50 votes. It was amusing to see Majority Leader Harry Reid try to salvage some credibility with liberals by declaring his support for all of these failing provisions. Mr. Reid won his last Senate race by running as a wholly owned NRA subsidiary. He and Mr. Obama are blaming everyone else for their defeat, but the meltdown took place in the Democratic Senate.

The rout also vindicates Republicans who wanted the Senate to vote on the gun bill as opposed to the Rand Paul-Ted Cruz faction who sought a filibuster. For once Democrats had to declare themselves in public and couldn't hide behind shouts of "Republican obstructionism."

So much for the first big liberal hope of Mr. Obama's second term. Maybe he should consider a centrist strategy from now on.