How is it unconstitutional to block islamic foreigners from entering the US, but constitutional to punish white citizens for being white?
First of all, affirmative action has very little to do with this debate. Most of what the supreme court has said about that topic relates to the U of Michigan cases and them giving admission preferences to minorities. To say that's punishing white people for being white is a radical oversimplification. If you don't like it, don't apply to the University of Michigan, or U Cal Berkley, or any of those liberal places you hate. Go to Jerry Falwell's school; I doubt they have an affirmative action policy.
And as far as blocking Islamic anything, the law may not, n-o-t...NOT, single out one religion. That's the express ticket to unconstitutionality. These orders were written by someone who had a high school level understanding of the law. That's why they hid them from the lawyers.
Now, Team Trump is scrambling to re-write those orders. But here's the rub. Let's say they publish a newly written order, approved by at least a few hand-picked rightwing nutball lawyers like Jeff Sessions, and then go to court on that one. A large portion of the court's analysis on the new order will be on its intent. Does it intend to discriminate against a protected class? Team Trump has to tell the judge with a straight face that even though the last one might have, this one doesn't, we promise. We TOTALLY changed our policy intent in just a few weeks. They're going to feed that line of sh!t to a judge, while constantly attacking through twitter, as Gorush put it, "my brothers and sisters of the robe." Good luck with that.