How Much Concern Should Closeted Politicians Have?

So, we're patting ourselves on the back for electing an African-American as our leader and Iceland gives us the big, "Oh yeah? Watch this." They've elected their first lesbian Prime Minister, Johanna Sigurdardottir. I can't even imagine how long it would be before this country could elect a gay, lesbian, or atheist President.

Responding to the news was Matthew Parris, a gay conservative MP in Britain who said to the BBC,

"Speaking from my own experience, I was sort of in the closet when I was an MP, and I always imagined that the world would fall in if people found out. Well, when I finally did come clean, it turned out most of my constituents had guessed already and didn't give a damn! ...They tend to hear the reactionary minority that speaks out against homosexuality, not the majority who quietly approve. If they came out, they'd be pleasantly surprised by the public reaction!"

Would this be true in the US? The voters of Louisiana haven't seemed too upset about David Vitter's visits to prostitutes wearing a diaper, but would it be different if it were Larry Craig? Is it a vocal reactionary minority or is the concern warranted?