We're not going to have a LGBT president.
People in the 1980s probably thought America would never have a black president.
With regards to the question at hand, I'd say it would be no doubt be a liberal Dem.
The problem is, who will it be? Also can this person win in this country's environment?
Problem is, Black people make up about 14% of the total population. LGBT people make up at most 2%. So the odds are way lower. Also, there's likely not going to be a presidency 60+ years down the line.
5-10% of the population is gay/bisexual.
It's less than 5 %. And there will not be one ever. End of story.