He doesn't want anyone who could be associated with terrorism to enter the US until we have the current situation.
It is not the Constitutional right of the Arabs, who aren't from the US, to have freedom of religion. That applies to US citizens.
Just because we allow freedom of religion in our US to our citizens, doesn't mean that there is freedom of religion for those who are NOT US citizens.
he's planning to take action against people in the united states and potential immegrants into the united states. you can't just say "we're not allowing muslims to immigrate anymore" because that actually violates the constitutional rights here, because other ethnicities are allowed to immigrate while muslims wouldn't be able to. that's denying people rights because of their religion, which is unconstitutional
but you're right, constitutional rights don't apply to other places, but in Annoying Orange's case i would expect his plans to be unconstitutional
also for the fact that they're not us citizens, after some google searching it seems that if these people were immigrating to the us we still have to give them some constitutional rights (i would expect the freedom of religion and the "you can't deny people their rights" parts of the constitution to apply)
edit: after some more research it appears the bill of rights does not apply to people who are in the process of immigrating but i wouldn't be surprised to find out that immigrants have religious freedoms similar to ones mentioned in the constitution
edit edit: after more research, the bill of rights does apply to immigrants as well as foreign nationals. what Annoying Orange is suggesting is unconstitutional