Marriage equality has been legal now in the State of Massachusetts for over two years. In Vermont, civil unions have been open to gay couples for six years.
Those who oppose legal recognition of same-sex couples often predict horrible consequences unless government bars these couples from equal treatment under law. It is reasonable to assume that if such dire events were taking place, those closest both geographically and in temperament would notice it first.
The New England states of Maine, New Hampshire, Vermont, Connecticut, Massachusetts, and Rhode Island are the states that are most likely to be impacted by the social experiments in Vermont and Massachusetts. And the recent attempt to amend the US Constitution to forbid gay marriage and overturn both marriage in Massachusetts and civil unions in Vermont would seem like the perfect time for them to declare their opposition if they had any concerns.
While New England can be considered liberal in temperament, its representation is far from partisan. Of the 12 senators from these states, 6 are Democrat, 5 are Republican, and 1 is an Independent. Of the 22 representatives, there are 16 Democrats, 5 Republicans, and 1 Independent.
Of these 32 officials elected to represent New England in the Federal Government, only one, Rep. Jeb Bradley R-NH, voted in favor of the amendment.
UPDATE It should also be noted that since October 2005, same-sex couples in Connecticut have been able to enter into civil unions that are virtually identical (for state rights, benefits, and obligations) to marriage.