Trump cited the 9/11 attacks as the reason for the ban and 15 of the 19 perpetrators of 9/11 were from Saudi Arabia. Saudi Arabia was not on the list. 

Two points:

1) Saudi Arabia's absence completely obliterates Trump's assertion that the ban was necessary because of "9/11" while at the same time lends credence to those who accuse Trump of Christian favoritism. 

2) It seems like more than just coincidence that no country that Trump does or has done business with, including Saudi Arabia, is on the banned list. And once again in the span just 16 days it seems that another Trump's decision was heavily influenced by his personal business dealings. 

The hypocrisy here is breathtaking because Trump and his supporters spent nearly 2 years screaming "crooked Hillary" and "lock her up" but the average Trump supporter, when faced with a blatant abuse of presidential power couldn't care less.