Destroying marriage is extremely important to utopian collectivists, otherwise known as Obama's base. He's shoring up that wing of his coalition here.
I think the issue helps Republicans more than democrats.
Correct. The destruction of the family is one of the goals of the radical left. Same-sex “marriage” is one of the many tools they are using.
The family is an obstacle to socialism, and must be destroyed in order to advance the power of the state, which is the left’s god.