>While I don't personally support the examples that I am aware of, I also recognize that in those specific cases the executive branch appears to be within the bounds of the law. I don't even object to the executive branch having the power to cancel the visas of political dissidents

It's my understanding that the 1st amendment applies to everyone, not just citizens. So if that's true (not 100% sure about that), how can political speech (protesting) be a valid reason to remove someone from the US?