The anti-pork brigade in Congress is poised to receive massive reinforcements next year, with nearly every non-incumbent GOP Senate candidate and hordes of House hopefuls swearing off earmarks themselves or even ready to consider an outright ban for all lawmakers.

That potential influx means a showdown with old-guard lawmakers - of both parties - who consider earmarking a central congressional prerogative. It also could mean a reversal of fortunes for critics such as Sen. Jim DeMint, the South Carolina Republican who has fought unsuccessfully to get his party to stop the practice.

"I will force a vote in the SenateGOP conference to ban earmarks next year," said Mr. DeMint, who has endorsed candidates supporting a ban. "I believe this will pass, and Republicans will be unified against the wasteful and corrupt earmark system"...