Rand Paul isn't running for state Governor, he is running to head federal government, in other words, gay marriage at the most influential level for public opinion and national acceptance of it.
Paul is OK with gay marriage, that means for millions of Americans in the military, federal employment and in immigration.
Paul didn't just come our in support of gay marriage, he mentioned "social issues". Rand Paul's liberalism on social issues, gay marriage for feds and immigration, and his immigration policy, are all big government positions.
As far as I know, Rand’s position on gay marriage is that he’s against it in principle, but wants to allow the states to decide whether or not to legalize it. So he won’t be in a position to legalize or not legalize on that level.
He is against federal imposition of traditional marriage, aka DOMA. He is evasive about DADT too, so he’s probably more okay with gay marriage than he lets on.
Like I said...it’s tolerable for me as long as he is openly against it, and does not advocate it or allow the gay marriage situation to progress further at any level of government. It’s far from ideal though, like temporarily staunching the wound while trying to save the country from fiscal disaster.