For the last time, the Supreme Judicial Court ordered the Commonwealth of Massachusetts to marry gay couples. A governor cannot legally defy a court order. If Romney had done so, he would have been impeached.
I suppose he could have followed the example of Alabama's Judge Moore, whose defiance of court orders sure did a lot of good! /sarcasm. Grow up.
The court never ordered Romney to do anything. It tried to coerce the legislative branch to endorse their little leftist revolutionary act. The legislature ignored them, and rightfully so. But, at the last minute, Romney stepped in and used his executive authority to enforce their completely unconstitutional lawlessness. The facts are clear no matter how hard the Romney campaign lies.
The proof is exhaustive, and is contained in the link I provided. It's so good, I'll provide it once again.