I have to agree with Mr. Conrad.

If it hadn't had been for the shirt, he would NOT have been asked to leave, which would mean that he was NOT trespassing.

Now, if he had been asked to leave for some OTHER reason, that would be a different issue.

As for any shop being allowed to exclude anyone the old "no coloreds" signs immediately spring to mind.

The wimpy fucking old "vote with your wallet" line again? Sheesh, you Merkins... Seem to think *everything* is about money, dontya? Words and phrases like "principle" and "stand up for your rights" are just incomprehensible *noise* to you, aren't they?
The US is driven by commerce. It is the only "culture" that we have.