Based on the vote earlier this year, DeMint would seem to have the votes to prevail in his anti-earmark campaign. But the earlier measure would have barred earmarks for both Democrats and Republicans. Tuesday's vote would only affect Republicans; majority Democrats could still seek earmarks — prospect that some Republicans say is unfair.
The upcoming vote also will be by a secret ballot, which means that anyone who publicly voted for the moratorium earlier this year could change their mind and not be held to account.
At the same time, DeMint is unpopular with many Republicans. He helped tea party favorites like Ken Buck, R-Colo., Sharron Angle, R-Nev., and Christine O'Donnell win their nominations but prove to be weak candidates in the general election.
GOP defenders of earmarks are invoking Obama — who endorsed an earmark moratorium the day after the election — in their campaign to preserve the practice. [Check out a roundup of political cartoons on the 2010 campaigns.]
"The only winner in this thing would be Obama, and I'm just not going to cede our authority to Obama," said Sen. Jim Inhofe, R-Okla. "I can't think of anything worse than to have all these great tea party people who I worked so hard to get elected come in and cede their power and authority to the president."
Inhofe says he expects to lose to DeMint next week after years of "demagoguery" by earmark opponents.
"Only Congress — not the president — appropriates funds," Sen. Lamar Alexander, R-Tenn., said in a floor speech earlier this year. "When Tennesseans come to see me about making Center Hill and Wolf Creek Dams safe or improving housing at Fort Campbell, my job is not to give them President Obama's telephone number."