I can't think of any pro-choice Republicans in the House and only a couple in the Senate. These pro-life Dems are not in danger of being challenged in a primary or being run out of the party I don't see the issue.
Richard Hanna
Also, here's all the House Democratic Yea votes on the Stupak-Pitts Amendment. Those in bold are still in Congress, italics are retiring this cycle.
Jason Altimire (PA) - Lost primary
Joe Baca (CA) - Lost primary
John Barrow (GA)Marion Berry (AR) - Retired
Sanford Bishop (GA)John Boccieri (OH) - Lost re-election
Dan Boren (OK) - Retired
Bobby Bright (AL) - Lost re-election
Dennis Cardoza (CA) - Retired
Chris Carney (PA) - Lost re-election
Ben Chandler (KY) - Lost re-election
Travis Childers (MS) - Lost re-election
Jim Cooper (TN)Jim Costa (CA)Jerry Costello (IL) - Retired
Henry Cuellar (TX)Kathy Dahlkemper (PA) - Lost re-election
Artur Davis (AL) - Retired, switched parties
Lincoln Davis (TN) - Lost re-election
Joe Donnelly (IN) - Now in Senate Michael Doyle (PA)Steve Driehaus (OH) - Lost re-election
Brad Ellsworth (IN) - Lost re-election
Bob Etheridge (NC) - Lost re-election
Bart Gordon (TN) - Retired
Parker Griffith (AL) - Switched parties, then lost GOP primary
Baron Hill (IN) - Lost re-election
Tim Holden (PA) - Lost primary
Paul Kanjorski (PA) - Lost re-election
Marcy Kaptur (OH) Dale Kildee (MI) - Retired
Jim Langevin (RI)Daniel Lipinski (IL)Stephen Lynch (MA)Jim Marshall (GA) - Lost re-election
Jim Matheson (UT)Mike McIntyre (NC)Charlie Melancon (LA) - Retired
Mike Michaud (ME)Alan Mollohan (WV) - Lost primary
John P. Murhta (PA) - Died in office
Richard Neal (MA)Jim Oberstar (MN) - Lost re-election
David Obey (WI) - Retired
Solomon Ortiz (TX) - Lost re-election
Tom Perrielo (VA) - Lost re-election
Colin Peterson (MN)Earl Pomeroy (ND) - Lost re-election
Nick Rahall (WV)Silvestre Reyes (TX) - Lost primary
Ciro Rodriguez (TX) - Lost re-election
Mike Ross (AR) - Retired
Tim Ryan (OH) John Salazar (CO) - Lost re-election
Heath Shuler (NC) - Retired
Ike Skelton (MO) - Lost re-election
Vic Snyder (AR) - Retired
Zach Space (OH) - Lost re-election
Jack Spratt (SC) - Lost re-election
Bart Stupak (MI) - Retired
John Tanner (TN) - Retired
Gene Taylor (MS) - Lost re-election, switched parties
Harry Teague (NM) - Lost re-election
Charlie Wilson (OH) - Lost re-election
Seems the main enemy of pro-life Democrats is Republicans, not other Democrats. Only Holden, Altmire, Reyes, Mollohan, and Baca lost to other Democrats, and those had more to do with redistricting (Holden, Altmire), ethics issues (Mollohan), or just plain unlikability (Baca).
