I have often said that the quest for marriage equality is the most bourgeois revolution since the 1840s. It would not be high on my personal list of priorities: however it is the current front-line of the struggle for civil rights in the US and as such am an ardent proponent of seeing it happen.
If there were any attempt to repeal or otherwise tamper with the
1138 benefits conferred on married people unavailable to those who are either single by choice or whose legal marriage is barred from being recognized on a federal level by DOMA, there would be rioting in the streets. Having marriages recognized strictly on a state level would result in just such riots to occur. So we're eventually going to have full federal recognition of same-sex marriages: it will just require the right case to be presented before the SCOTUS.
The genie is out of the bottle: it's not if but when. My guess is it'll take no fewer than fifteen years, no more than twenty-five; social change in the US is glacial but reasoning eventually does prevail.