Thursday night on Fox News Channel’s “Hannity,” former New York Mayor Rudy Giuliani said Republican presidential candidate Donald Trump’s proposed ban Muslim for entering the Untied States would violate the First Amendment of the Constitution.

Giuliani said, “I think we have to be very careful about who we let in. I don’t think we should let any of the refugees in. I think they should be put in a safe zone in Syria, but if you do a ban on all Muslims, I have no question that you violate the first amendment. The reality is if you let no one in, you could say well, they have no Constitutional rights but once the government sets up a system, the government cannot discriminate in the way it applies that system. So the minute the government sets up an immigration system it can’t use religion as a test or race or gender as a basis for why someone can’t come in.”

He continued, “We have to tell people things that are realistic. Thousands and thousands of Egyptian people from Dubai, people from the Arab Emirates, we do business with them. We own businesses there, they own businesses here. We trade oil, natural gas.”

He added We don’t have a right to ban all Muslims…How do you stop a businessman who’s been coming back and forth to conduct his business every month. You cannot establish a ban on all Muslims, And also if you did that, you would really take that population and start radicalizing a lot more of them if you did it. To me, it’s not a sensible proposal.”