(or will be ready) for a:
Black-By the 1980s or so.
Woman-Possibly as early as the 1960s.
(Non-Closeted)Gay-Probably within a few years
(Non-Closeted)Atheist-A couple decades, maybe earlier
Muslim-Probably in a few years, when the War on Terror begins to settle down
Jewish-1950s?
Hispanic/Latino-Probably some point in the 20th century, but it depends on how white they are.
Asian (Far-East)-1970s, after the Vietnam war
Asain (Middle-East)-See Muslim, though Lebanese and Arab Christians could probably win a lot earlier
Asian (India/Whateverstan)-Now; Indians have a decent reputation, and if they can win in the Deep South...
Pacific Islander-See Far East?
Native American-No idea. Wasn't Coolidge part Indian or something?
Socalist-There were points where a socialist could win, but probably not now. With a decent campaign, easily in certain points in the future.
Anarchist-Too ideologically...unique to ever be elected
Robot-Never
I'll go with that. Except for robot. John Henry Eden will be "elected" the President of the Enclave in 2271.