I've never heard an argument against gay marriage that wasn't based in religion or "traditional" morals. There is no rational argument against gay marriage. Withholding marriage from people based on factors they can't control like their loveuality is morally wrong. Even if you argue that marriage is a religious or traditional institution, gay people should be allowed to exercise the same rights that married straight people get. For example, a marriage partner is always considered family in situations where their spouse has been in an accident and is unable to communicate who they want to be able to see them. (as in they're passed out or whatever) Gay people aren't afforded this privilege.
To me it's more about the principle. Getting married (as in getting a marriage license, not having a wedding or whatever) isn't
extremely important, but withholding a legal privilege from someone based on factors beyond their control is wrong. That's why gay marriage is the hottest GSM issue; getting majority support would signify a growing acceptance for GSM people from the American public.
ok, so people can't forget dogs because they can't give consent, why is incest not allowed.
it doesn't matter what unlawful thing i bring up, the want and urge to do something should not make it alright and should not be an argument at all
if it's between two fertile members of the opposite love, there's a heightened chance that a child they bear will have birth defects or genetic problems.
beyond that there's really no rational justification against it. sure we may find it morally deplorable but there's not really any harm being done, it's just weird. if your only argument is that it feels wrong, and not that it has some negative effect, then you have no argument.
It's funny to see kids like warble parroting what their parents spew at them about the decay of society and stuff. People forget that this happens every generation. This happened with interracial marriage, with women's suffrage, with the prohibition of slavery.