The result is that, while the defunders will get their vote in the Senate, they laid no groundwork—no sustained or coordinated advertising or Web campaign, no public uprising in key states—to pressure Democrats to vote with them. This is an error of embarrassing proportions. Five Democrats isn’t a lot, especially in the context of an unpopular law. On Thursday, West Virginia’s Joe Manchin—who isn’t even up for re-election—became the first Senate Democrat to support delaying the individual mandate for a year. While it isn’t “defund,” it’s a big crack in Democratic unity.

Now imagine if, over the past months, the conservative dollars had been spent flooding the airwaves with ads demanding that Ms. Hagan justify an ObamaCare exemption for big business but not for average families? Or on ads pinning soaring premium-prices on Mr. Pryor? Or if Heritage Action—instead of holding its Defund ObamaCare rallies in Tennessee and Alabama (to target Republicans already opposed to ObamaCare)—had focused its events in Louisiana, inspiring voters to swamp Ms. Landrieu’s office with calls? Or in Colorado (Sen. Mark Udall) or New Mexico (Sen. Tom Udall)?

The defund coalition will claim we wouldn’t be having a vote if they hadn’t dragged their colleagues along in the first place. We’ll never know. The defund ringleaders this summer couldn’t be bothered with the hard work of calling internal meetings with their colleagues—soliciting input, selling the idea, formulating a strategy, getting people on board.