Are businesses allowed to have dress codes? Some places don't allow saggy pants and get away with it, so I don't see why this would be any different.
If, when defending your support for Donald Trump, and your response is,
"But but but... HILLARY!!!", then you lost the argument before you even began.
YouStar is right about one thing though, we're headed in that direction. Google Glass isn't just a trend, it's gonna get smaller, slicker, and everyone will have something like it.
And in another decade or so, they'll make contact lenses that do the same thing. People won't even know you have them on.
When operating a business like a store or restaurant, one's customers are invitees. You can evict trespassers for whatever reason you want. You might even have to for injury liability coverage. But you cannot evict licencees and invitees without certain circumstances.
I'm too drunk right now to spell all of this out any more clearly.
Liberté. Égalité. Fraternité.
It's not breaking the law to enter with, say, no shoes or a gun or Google glasses, but to refuse to leave when asked is trespassing...which is a crime.