I think he is stating the traditional religious argument against homosexuality and hence homosexual marriage.
That homosexuality is a choice, not an imbalance of hormones or series of events altering the sexual preference and behavior of a person.
Homosexuality is a natural occurrence, it is something that animals, humans and more than likely aliens, partake in every single hour of every day and have done so ever since the dawn of time.
Making homosexuality and homosexual relationships legally recognized is a step in the right direction. Persecuting someone for their sexual orientation is just as bad as persecuting a race. It is something that the individual has close to no control over, sure gays can FORCE themselves to be straight, but that's like forcing an African tribesman to dress in an American style, speak English and adopt Christianity........ *cough , effing, cough*. Your not going to change the fact that this person is gay, or this person is an African. You are simply forcing them to work to your idea of what they should be and in a land supposedly calling itself "of the free" that is inherently wrong.