I am entirely for gay marriage or whatever you want to call it. The State has no business dictating who you love or how you love. That being said, since the State is already so engrained in the marriage question, this is one subject where I think a federal initiative would benefit.
I say this because when I was trying to convince some of my liberal friends that a Ron Paul presidency wouldn’t mean an outright ban on gay marriage as many of the other Republican candidates advocated, and that RP would leave it up to the states to decide, a gay friend of mine laid bare some facts I had not previously considered.
He went to university overseas and fell in love with a foreign man while there. If gay marriage were left up to the states, it still does not allow his partner to emigrate to the US on a spousal visa because that is a federal issue, not a state issue. He also brought up the issue of filing taxes. While at the State level they could file a joint tax return, when they do their federal return they would have to do a completely different tax return because the federal government doesn’t recognize gay married couples like they do heterosexual couples.
If the role of government is to protect liberty, then the freedom to marry who one chooses and to not be treated differently for this just because the person you love is of the same sex needs to be protected not only at the state level but at the federal level. This should hold true whether you think this is a lifestyle choice or whether you believe people are born this way. Like other choices, libertarians do not believe the State can regulate and legislate people from making bad choices. If you believe homosexuality is merely a choice and not innate, adhering to libertarian doctrine means still accepting this and protecting this choice as on the basis of any morally questionable choice an individual makes that does not harm any other individual such as how libertarians advocate for drug legalization.
As it stands, my friend and his partner are living in Australia as they can both get temporary visas there while they try and figure out their future. Also, my husband is Australian and when looking at spousal visa requirements for me to move to Australia, I noticed that the Australian government is fully accepting of gay married couples trying to get spousal visas for their partners. So it seems the U.S. is behind other nations in this regard.