I tried to post this same message myself but couldn't get the link correct.
Although I am an Iowa Hawkeye (my boy, however is currently in the COE at Michigan, boo) I never really considered the Wolverines as a nationwide gang -- the reason for the school's band on the student's UMich t-shirt.
If they want to ban college wear, they should ban ALL college wear, rather than carve out an exclusion for the state schools. Maybe there is a compelling reason (not the the wolverines are a gang, but that local gangs "borrow" their colors), but it seems silly to ban it in the younger grades. If you're going to impose a ban at the HS level, what's to stop the gangs from adopting the local school colors? It sounds like they carved out an exception because otherwise the policy would be too unpopular - well, too bad. Either the gang problem is bad enough to enact a ban, or it isn't! Imagine the HS Senior who is accepted to UMich, and can't wear their t-shirt, while his classmates who choose to stay in-state can, or the student whose older sibling attends Harvard or Princeton (or wherever else).
Truthfully, I don't mind that they are enforcing this, even on a kindergarten student. If the dress code is the same and enforced all through school it shows consistency. Why would it be okay for a 6th grader to wear something but a 7th grader can't? Better to set the standards and enforce them everywhere. It isn't as if the tyke was taken out of class.
One of my favorites, too! Maine Longhorn, how about this one: Why doesn't Texas fall into the ocean?
Because Oklahoma sucks!
As to the earlier posters, I agree, either ban all sports team t-shirts or none, no in-state favoritism. My California recently graduated high school S was born in Texas and UT shirts were the majority of his wardrobe until he started college. In fact, he still wears them a lot even though he has started at a UC.
This wouldn't happen in Ohio. In our local district you typically see a few students K - 12 wear U of M shirts and when OSU plays Michigan, there are always some Michigan shirts along with OSU. Many Ohioans graduate from that school up north and I'm one of them.