The House’s new Democratic majority is flirting with disaster as it guts key provisions of the strict lobbying reform it promised voters last November. Rebellious lawmakers, worried about their own career path, fought their leaders to defeat tighter restrictions on the sleazy, revolving-door culture by which members of Congress move on from an apprenticeship of merely serving the people to real Washington money as insider lobbyists.

“What you are telling me is I cut off my profession,” one Democrat, Representative Michael Capuano of Massachusetts, complained in baldly defending the vox pop-to-riches scheme.

Such crass considerations defeated a proposal to make congressional alumni wait two years, not the current one year, before lobbying old colleagues. Now the rebels have even bigger game — the “bundling” proposal to make power lobbyists disclose the outsized campaign funds they raise from individual clients and package as one big donation.

This vital reform, like the revolving-door pledge, was a part of the “Honest Leadership and Open Government Act” fervidly promised by Democrats last year in denouncing the quid-pro-quo corruption that saw a few leading Republicans driven from office and on to prison.

For all the promises, the bundling disclosure mandate is in deep trouble as opposition mounts from Blue Dog, Hispanic and black caucus Democrats intent on protecting their re-election campaigns. The pity is that the proposal they are fighting doesn’t even stop this ethically indefensible practice — it merely puts the details on the record.

House Speaker Nancy Pelosi knows failure to approve bundling disclosure will reduce the Democrats’ vaunted vows to political farce and shorten their chances of retaining the majority. Republicans are chortling, but the smarter moderates in their ranks better keep their eyes on the people’s agenda, not the lobbyists’ A.T.M.’s. A crucial vote over the lobby bill’s debating rule is about to determine whether reform dies at the hands of greedy incumbents. They might remember that next year’s voters will check for enactment of last year’s promises.