Same sex marriage isn't bad for US society. If a man loves a man, let them be together. They aren't doing anything bad to the US by loving each other. Neither are women who love other women. They're not causing the end of the world by loving the same sex, so they aren't affecting US society by loving each other.
It's funny to see conservatives claim same-sex marriage compromises America's strength (how?) when they are the most vocal supporters of the institution of marriage. Banning homosexuals from marrying just weakens marriage by preventing people from entering into these institutions. So much for their belief in the benefits of marriage to society.
No, same sex marriage does not compromise the strength of U.S. society, because the American melting pot is still the strongest, most accepting country in the world. The homosexual population is a minority. Most people do not spend a lot of time thinking about them or same sex marriage. This is not to say they don't care. It is just that same sex marriage is not an issue that affects a lot of people, so it is not likely to alter America or American unity very much. Most people accept what other people do.