No offense meant to the interviewers here, but Rep. Matt Salmon (a Class of 1994-er who won back his old seat in Congress last year) says a lot in this video. He says his son is gay; learning this, he says, did not change his opinion of gay marriage. But he doesn't slam the door on that, does he?
I don't believe that this is a lifestyle he chose... I'm just not there as far as believing in my heart that we should change 2000 years of social policy... I haven't evolved to that station. Rob Portman apparently has.
The beauty of "evolving," as John McWhorter has explained, is that it implies a happy lurch toward one position. That position is increasingly popular, in and outside the media: "these evolutions seem always to be towards targets that will lend political advantage." I see a small amount of conservative chatter praising for Salmon for holding tough, but he's not saying he always will. If you're "not there yet," you're trying to get there. This is how people talk when they're trying to kick drugs or say yes to new jobs.
UPDATE: And here's Sen. Bob Casey, the man who kicked Rick Santorum out of the Senate.