It's something OTHER than race, apparently. If we go with the author of your study, it has to do with "religion and stuff" based on his regression models. Being black is not even statistically significant - there are better predictors of bigotry than race.
His words again:
race not so much (not even statistically significant)
Maybe you should focus on the factors that are more indicative, like religion. I guess it's not as flamboyant a headline when you put it that way - Religious people are more bigoted than non-religious people definitely doesn't sound as good as "black people are more homophobic" - but that's a more realistic headline.