at least if it is a liberal or Democrat. Gays couldn't serve openly in the military until 2010. No openly gay people were elected (as opposed to reelected) to any Congressional seat until 1999 (Tammy Baldwin) the first gay male and 2nd openly gay Congressman elected was Polis in 2008. Only Baldwin has been openly elected statewide as a gay person.
Gays have a hard time having a path to the nomination. Gays are spread out and the first states either have no gay centers (Iowa, New Hampshire) or have gay centers that are outweighed by the rest of their states (the South). Obama and Clinton both had large constituencies in the party which allowed them to win the nomination in essentially two way races. For Obama it was a combination of anti war voters in Iowa and New Hampshire combined with African Americans in the South. Once the big states of the midwest voted he already had an insurmountable lead. Clinton did the same thing with Hispanics, African Americans, and women. She won the nomination on Super Tuesday. That same electorate doesn't have a natural group for an openly gay politician. Las Vegas, Miami, Dallas, Houston, Atlanta, New Orleans are all well known gay areas but are overwhelmed by the rest of their states (except in Nevada). I don't see a path in a two way race. I also don't see, other than Baldwin and maybe Polis (who is running for governor in Colorado) any gay politician that would be in a place to be seriously considered for President. While Obama wasn't the most experience politician ever by any means, he was a sitting US Senator who had been elected statewide who was in his fourth year of service when elected. Polis, even if he won in Colorado would be in his second year as governor while Baldwin would be in her 8th. I am skeptical that any woman can be elected anytime soon after what happened to Clinton.