Joe Donnelly (D-Ind.) and Glenn Nye (D-Va.) talk before a Blue Dog meeting in September 2010. Nye lost that fall; Donnelly is running for Senate. (Evan Vucci/AP Photo)

In the 2012 elections, redistricting is likely to further chip away at the once-powerful group, as members are placed into more Republican districts or forced to compete against more liberal Democrats.

Blue Dogs have a brief but notable history. The caucus was formed in 1995 after Democrats’ stunning losses in the 1994 election. Their ranks grew dramatically in the 2006 Democratic sweep, and they had a major impact on last year’s health-care reform debate. In the 2010 elections, another Republican wave decimated their ranks.

The group had 54 members in the 111th Congress; it now holds less than half of that number at 25, and three of them are retiring next fall. Former Rep. Jane Harman (D-Calif.) already left Congress to helm the Woodrow Wilson Center.

With that in mind, The Fix gives you its rundown of the remaining Blue Dogs and who will still be standing post-2012.

Vunerable (4):

* Jason Altmire (PA-4):Altmire will likely be drawn into the same district as fellow moderate Rep. Mark Critz (D), and only one of them can survive. Altmire has raised more money and has (slightly) more seniority; both Democrats won by slim margins in 2010.

* Leonard Boswell (IA-3):The new Iowa district lines have Boswell facing Rep. Tom Latham (R) in a swing district. Boswell represents more of the new district, but he’s been a GOP target for years and Latham is a close friend of House Speaker John Boehner (R-Ohio).

* Mike McIntyre (NC-7) :The new North Carolina map would likely force McIntyre to move to stay in his current seat, and the seat will become significantly more Republican. Iraq veteran Ilario Pantano is planning to run against McIntyre again, but he’s probably not the strongest GOP candidate.

* Heath Shuler (D-N.C.): Shuler flirted with retirement in 2010, and he is reportedly considering taking a job at the University of Tennessee. The current GOP redistricting plan makes him more vulnerable.

Potentially vulnerable (12):

* John Barrow (GA-12): Republicans control redistricting in Georgia, and Barrow’s marginal district could be made more Republican. However, the GOP might risk a Voting Rights Act lawsuit if the party takes that path.

* Sanford Bishop (GA-2): Bishop is in the same boat as Barrow. However, Republicans will likely make this district more Democratic to help Rep. Austin Scott (R).

* Dennis Cardoza (CA-18):Under the current bipartisan redistricting proposal, Cardoza might get a more difficult district or be drawn into the same district as another incumbent.

* Ben Chandler (KY-6): Chandler won by the skin of his teeth in 2010 — by a mere 647-vote margin — and his opponent, lawyer Andy Barr, is planning to run again. But redistricting in the divided legislature could make this Republican-leaning district more Democratic.

* Jim Cooper (TN-5): This marginally Democratic district is an easy target for Republicans who control redistricting, but there’s a chance the GOP will choose to shore up their own members rather than go after Cooper.

* Jim Costa (CA-20) Costa might be drawn into the same district as Cardoza. Costa could avoid an incumbent battle by moving to a new Democratic-leaning district to the east; Cardoza has pledged to stay put.

* Gabrielle Giffords (AZ-8):Giffords would have little trouble winning reelection, but it’s unclear whether she will be able to return to Congress in 2012. Her chief of staff is cautioning observers not to read too much into Giffords’ incredible recovery from the January shooting in Tucson.

* Tim Holden (PA-17): Republicans could dismantle this seat in redistricting, but Altmire is the more likely victim. Holden won decisively in 2010 despite his GOP-leaning district.

* Jim Matheson (UT-2): GOP-controlled redistricting is expected to imperil Matheson. And a Democratic proposal would make his district more liberal and open Matheson to a primary challenge from the left. There’s a good chance the state’s lone Democratic House member will jump ship and run for Senate or governor.

* Loretta Sanchez (CA-47): Preliminary maps give Sanchez’s district a slight Republican edge. It’s not as bad as it could have been, but Republicans will probably target Sanchez, the only Democrat in Orange County.

* Kurt Schrader (OR-5): The two-term congressman’s swing district becomes a little more Republican under bipartisan redistricting plans.

* Adam Schiff (CA-29): There’s a chance Schiff will be drawn into the same district as a more liberal Democrat and struggle to win the primary. The last two “visualizations” from the redistricting commission pit him against Rep. Henry Waxman (D).

Safe (6):

* Joe Baca (CA-43):Baca is expected be drawn into a Democratic district with Rep. Jerry Lewis (R), meaning the five-term House member is likely safe.

* Henry Cuellar (TX-28): Cuellar, one of the most conservative Democrats in the House, got significantly safer under Republicans’ redistricting map.

* Mike Michaud (ME-2): Democrats aren’t expected to have trouble in Maine, although Republicans are trying to speed up the redistricting process (set to be completed in 2013) to give them a chance at Michaud’s seat.

* Collin Peterson (MN-7): Peterson routinely outdoes his party at the polls. His Republican opponent got only 38 percent of the vote last time around, and the GOP wants to make his district more Democratic, not less.

* David Scott (GA-13): There’s an outside chance that Republicans will target Scott in redistricting, but Bishop and Barrow are much more likely victims.

* Mike Thompson (CA-1): Thompson is currently in an overwhelmingly Democratic district. The lines will shift, but he will probably have a safe seat.

Retiring/Leaving House (3):

* Dan Boren (OK-2)

* Joe Donnelly (IN-2)

* Mike Ross (AR-4)

After the 2010 elections, Blue Dogs expressed hope that they would become more powerful in Congress as House Speaker Nancy Pelosi’s power was diminished. That hasn’t been the case. Outside of another huge Democratic victory — which looks very unlikely — this group will likely be further marginalized in the next election.

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