Political Shirts in Schools

My neighbor went to pick his child up at a local public school. He noticed a teacher wearing a "President Obama" shirt. He called the school Board, and was told, school staff were not supposed to be political, and the matter would be addresses. A few day later, when picking up the child, a couple of teacher's aids walked near him. One was wearing another Obama shirt, and, in loud tones ment for my friend to hear, they said, "I see Ya sport'in  some Obama, good fo' you"! What is the policy reguarding this issue. It's not sour grapes, but, I wouldn't want my child to be exposed to blatent politics one way or the other.