You said that a vast majority of the American population opposes same-sex marriage. I said that it doesn't. All polls taken in 2012 confirm my opinion.
Now you are switching the discussion to whether or not it is legal. Most states have a constitutional ban on same sex marrige. This does not mean the vast majority of the population of that state opposes gay marriage. It means that State laws have not kept up with public opinion.
Sorry, I don't think this is true since most of the laws against same sex marriage are recently passed laws or amendments to state constitutions. It's rather that special interests frighten state legislators and/or that state legislators tend to be conservative. Also a nationwide poll can be pretty meaningless when it comes to a specific state.