In the film, the guys embark on a night of drunken and drugged up debauchery only to wake up with a wrecked hotel room, a stolen tiger, a chipped tooth, the groom missing, a stolen cop car, a naked Asian gangster in their trunk, and stuck caring for a mysterious baby. Not to mention terrible hangovers.
The shirt, proclaiming Obama to be worse than a hangover, seems to be implying that America got all drunk on hope & change & Bush hate and ended up with the country in disarray while stuck with Obama.