First he supports abortion/stem cell research, then he comes out in favor of a minimum wage increase and now full equality! And to think he actually voted for the Federal Marriage Amendment 8 years ago. Either our little Denty is growing up or we're starting to see a break from the establishment not only to make the party more accepting come 2016, but that it's common sense the right thing to support.
I definitely would have though Gerlach would have been first given his support for LGBT Hate Crimes and voting against the constitutional amendment, but hopefully he does it sometime before he leaves office. Fitzpatrick should be soon to given he's got to survive a tough re-election fight this year. Justin Amash, Walter Jones, Jeff Denham, David Valadao, Chris Gibson, Bob Gibbs, Mario Diaz-Balart, Joe Heck, Greg Walden, Pat Meehan, Frank LoBiondo, Leonard Lance, and Rodney Frelinghuysen could be among the next potential House Republicans to come out in favor of marriage equality. Collins will almost certainly be the 4th Republican in the Senate to do so followed by Heller and Hatch and I could see Burr, Toomey or Ayotte supporting it down the road to.
btw, among the "Democrats" who still oppose marriage equality in the House are:
John Barrow (D-GA), Bluedog Coalition Chair
Mike McIntyre (D-NC)
Jim Matheson (D-UT)
Nick Rahall (D-WV)
Sanford Bishop (D-GA)
Henry Cuellar (D-TX)
Pete Gallego (D-TX)
Filemon Vela (D-TX)
Bill Enyart (D-IL)
Dan Lipinski (D-IL)
And in the Senate, Mark Pryor (D-AR) and Joe Manchin (D-WV) are the only 2 opposed to SSM, but you could argue Mary Landrieu (D-LA) is, to given she backs LA's ban on it. John Walsh (D-MT) hasn't given his view on it, yet, but it seems he would be leaning towards supporting SSM.
I bet some of the Congressional Black Caucus opposes same-sex marriage, especially the older members. I think Rangel falls into that camp.