Well I would hope that no one on this board is a bigot, but I would say that it is a much more complicated issue than simply saying it's entirely due to genetics or it's entirely a lifestyle choice. As with most complex human traits, the reality lies somewhere in the middle. The reasons behind or origins of homosexuality are not dichotomous but moreso a complex combination of genes, environment, and personal choice. If it were entirely genetic, then his identical twin Jarron should also be gay, which he is not. However, there is definitely a genetic component, as twins do have a higher likelihood of being homosexual.
http://www.ncbi.nlm.nih.gov/pubmed/1845227
And then, there's also the question of evolutionary sustainability if it is entirely genetic.
I believe human sexuality is defined by a complex spectrum of inputs. If even a simple trait like physical height has genetic and environmental contributions, then a much more complicated one like human sexuality is assuredly even more complex.
Of course, the opposing sides will never frame the issue in such a nuanced light. It is undoubtedly a very interesting and complicated question, worthy of enlightened discussion. Not sure how that fits into 140 characters on Twitter though.