There is a nice breakdown of the poll from the FFN that came out last week from Marry in Massachusetts:

In the family of nations, the U.S. remains right leaning. Massachusetts and Vermont though have been slowly changing minds. Each has a multi-year history of SSM or civil unions. Both have extremely low divorce rates.

If there is an argument and conclusion here, it would be that SSM strengthens marriage. At at time when the rest of the nation is seeing a long-term (far predating SSM) decline in marriage and increase in divorce, that should be welcome news to traditionalists.

This hightlights the question that no one who opposes SSM seems to be able to answer: Why does marriage need protection from serious and committed people who what to participate in it?