Married men: for Romney by 54-35, Romney's margin 19.Some of these differences are sharper if you factor out ethnic groups. More and more, votes are predictable by demographics.
Married women: for Romney, 49-42, Romney's margin 7.
Single men: for Obama, 47-38, Obama's margin 9.
Single women: for Obama, 60-31, Obama's margin 29.
I argued below that this election may not be determined by the undecided swing voters, but rather the demographics of who votes.
If Obama is re-elected, then the Democrats will have an incentive to pass laws and policies that favor the demographics that keep them in office. In particular, they will expand their anti-marriage laws and policies.