Smh... I heard that there's a text message going around stating that if u wore a shirt that is supporting that's representing the candidate you want to vote for, they'll send you yah ass back home Check Di Linki
Many places don't allow you to "campaign" within a certain amount of metres from a polling station; Obama t-shirts are a form of campaigning, that simple. The same way you can't wear a button with who you support when you go vote.