A federal judge in Massachusetts struck down DOMA as a violation of the 10th Amendment. It set the tea party pot boiling. Conservative's hair burst into flames. It was folly, pandamonium ruled...save the kids, bury the silver.
It might just boil down to the simple fact that the states and local jurisdictions within the states issue marriage licenses (depending on the state). There is no Federal Marriage License so there is no law or set of regulations from that source and as states go, requirements, waiting periods, etc. vary from state to state.
If you think about it, and some do, a marriage license granted by the state is as much of you can be married as it is "here are the rules". With the permission comes the stipulations. A marriage license granted by a state means simple that permission is extended and you abide by the rules that surround it and the act of marriage itself.
DOMA takes away one part of the state's interest...that of the rules that govern marriage within the state. That was the distinction without a difference the judge was getting at...and that is what the 10th amendment so clearly states.
Are we clear?