Where have you found it?
In Boston it was on tap, may or may not come back:
Redbones (kicked in 12 hours 3/20-3/21)
Publick House: has a keg in house and will go on tap in the next few days according to some guy I talked to
Wasn't on tap/no info:
according to the press release:
Sixpoint Craft Ales today announced the release of the "Hop Obama" ale in both New York State and Massachusetts. Beginning next week, all supporters of the democratic process will be able to hoist a glass of this limited-edition beer that was brewed in tribute to the inspiration that has been Senator Barack Obama's presidential campaign. The beer will be available in finer bars and restaurants for a limited time throughout both states. It is expected that the beer will only last for the duration of the Democratic primary hiatus, which begins Wednesday, March 12 and extends through April 22.