I don't know about this guy's video who says we're in the "last days," but it does provide an angle to this story that hasn't been considered: I don't think he was kicked out for the front of the shirt, which says "JESUS SAVES." I think he was asked to leave for the back of the shirt, which has other religious symbols in that "COEXIST" pattern, but it's crossed out. He has crossed out others' symbols of their faith. That's a bit more inflammatory.
HOWEVER, does that mean he gets kicked out of the Mall of America? It's private property, so I guess they can do what they want. But they're not getting any support online, based on posts that I've seen.