Don’t look now, but all is not smiles and cheers on Arlen Specter’s (new) side of the aisle.  Harry Reid agreed to allow Specter to keep his 28 years of seniority when he crossed, meaning that Specter will jump the line on committee assignments, especially in chairs.  Other Democrats who expected to get dibs are crying foul behind closed doors, and hint that they may renege on Reid’s deal:

Several Democrats are furious with Reid for agreeing to let Specter keep the seniority accrued over more than 28 years as a Republican senator. That could allow him to leap past senior Democrats on powerful panels – including the Appropriations and Judiciary committees.

One senior Democratic lawmaker told The Hill that the Democratic Conference will vote against giving the longtime Pennsylvania Republican seniority over lawmakers such as Sens. Tom Harkin (D-Iowa), Barbara Mikulski (D-Md.) and Dianne Feinstein (D-Calif.) when they hold their organizational meeting after the 2010 election.

Specter was elected in 1980, and under his deal with Reid would jump ahead of all but a few Democrats when it comes time to dole out committee chairmanships and assignments.

“That’s his deal and not the caucus’s,” the lawmaker said of Reid’s agreement with Specter.

According to Alexander Bolton, the most likely to be unhappy is Tom Harkin, who might lose his chair at a key HHS subcommittee.  The Democrats on the Judiciary Committee might also object if Specter takes Pat Leahy’s spot if Leahy gets the Appropriations chair.  Specter might also get the Appropriations slot if Leahy stays put, which would really touch off a row, since that’s the most coveted position for porkers.  Barbara Mikulski would lose her bid if that happened, and she’s also not likely to quietly accept her fate just to save Specter’s electoral bacon.

Senate Democrats tell the Hill that they have no reason to keep Reid’s commitment to Specter.  In fact, they think they’ve done enough for the Pennsylvania Republican, who was obviously about to lose his primary race to Pat Toomey in 2010.  As far as they see it, they allowed Specter into their caucus, which bumped other Democrats who intended to run for Specter’s seat in 2010, including Rep. Joe Sestak.

Given Specter’s baldly pragmatic reasons for switching, they don’t see the need to cough up plum committee assignments to a man who all but announced that he’s joining the caucus despite his policy preferences, and not because of them.  It’s hard to blame them, either.  It would be poetic justice if Specter discovers that his new pals want less to do with him than his old colleagues in the GOP.