Just Desserts (Just No Sammiches)

[Sheldon]

I also admire her ethical stance, and they may of course choose to fire her for it, but I wouldn't be too sure. I imagine they already have a dress code policy for customers, or I'd be surprised if they did not. If hate speech emblazoned on clothes does not violate it, they could at least in theory find their premises hosting a Klan gathering, or the local chapter of Nazis. Or as I said earlier t shirts emblazoned with bigotry directed at religious demographics, antisemitic epithets, a cartoon of mohammed? 

I doubt they'd want to go in that direction...it seems more likely they will clarify a dress code was enforced.

I doubt it. It's more plausible that it falls under the right to refuse service, not dress code. I can't imagine a dress code that would cover all manner of speech/dress that some might find offensive.

Google offensive t-shirts and get back to me if you find it necessary.

Well a violation of a dress code, would legally justify the right to refuse service, as long as it is applied universally of course, so they're not mutually exclusive. Though I admit I am far from au fait with the relevant laws in the US.

I can't imagine a dress code that would cover all manner of speech/dress that some might find offensive.

Since these are business premises it wouldn't need to, would it? The company gets to decide what they deem offensive, or not.