As best I can tell, the question didn't appear until 1992. It's possible that it was asked in the Voter News Service polls that were conducted during the mid-terms between 1994-2002 (and maybe even before that, if they provided them then), but you need a Roper Center membership in order to access those. Remarkably, or perhaps unremarkably, the gay vote has been relatively static for the past 20-something years.
1992: 72% Clinton
1996: 66% Clinton
2000: 71% Gore
2004: 77% Kerry
2006: 75% Democratic
2008: 70% Obama
2010: 69% Democratic
2012: 77% Obama
2014: 76% Democratic
Temporarily racist gays!? 
Source: 1992 ( Page 8 )
Source: 1996
Source: 2000
Source: 2004-2012
Source: 2014
I wonder whats the demographic profile of those 30% of gays who vote for the GOP candidate. My guess is that some of it is trolling/checked the box by mistake. While the rest are probably either wealthy gays OR gays that are quite religious.
More issues factor into LGBT peoples' voting habits other than just gay rights. You can think that Republican economic and defense policies are the best, and most of their social issues other than gay rights.
I voted Republican in the 2014 elections, mostly county-level officials and for U.S. Representative, because Lake County, Indiana has a serious corruption issue as a Safe-D county. If I lived a few hundred feet more to the west, in Illinois, I would've voted for Rauner because the IL Democratic Party is just plain awful. Protections for same-sex marriage and anti-discrimination laws are fine and good, but if I can't find a job or build wealth, then I might as well just move to some sunbelt hellhole where I'd be discriminated against either way.
1996, 2004, and 2012 are understandable because of Bill Clinton's signing of DOMA, GW Bush's and the broader Republican Party's crusade against the gays that year, and Obama's endorsement of SSM, respectively (though I'm a smidge surprised Romney's avoidance of the issue didn't cancel some of that out).
If President Griffin's numbers above are for LGBT people, well I've come to know
a lot of bisexual Republicans (see this forum as well).
Also, be sure to factor in the margins of error for such a small subset.
