I have always supported ban to Refugees. But I do not understand why a person who has already got his/her greencard should be denied entry into USA because he/s

I have always supported ban to Refugees. But I do not understand why a person who has already got his/her greencard should be denied entry into USA because he/she belong to one of the 7 nations. Pakistand and Saudi Arabia are conveniently not included. I hope these nations respond by confiscating any/all American assets around their territory and expelling American ambassadors.