The ultimate goal of the fight for marriage equality is one of the following:
1) A Supreme Court ruling that the constitution, as it stands, protects the right of gay marriage throughout the country.
2) An amendment to the constitution explicitly protecting the right of gay marriage throughout the country.
3) Individual protection in each US state and territory for the right of gay marriage, plus recognition under federal law.
(It's certainly worth fighting for other just causes, such as marriage equality in an individual state, protection against discrimination, and so forth. But it seems to me to be important to keep the ultimate goal in the fight for marriage equality in mind.)
It seems to me that option 1 is by far the most likely. Reelecting Obama could very well get us to option 1 before 2016. Electing Romney could very well pack the Supreme Court with conservative justices, pushing back option 1 for decades.
Let's keep our eyes on the prize.