It's a constitutional issue in some sense (executive orders --but Obama was pretty much unchallenged) due process? Tell me which country will grant me (a foreigner to them) due process upon denial of entry into their ports of entry.

Its not unconstitutional to issue Executive Orders. It is unconstitutional to deny equal protection of laws to green card and work permit holders. Or at least, a Federal Judge thinks there is a strong enough case to issue an injunction to this particular Executive Order. I had no issues with the other orders that Trump issued, fwiw.

No, it's a constitutional issue in the sense that it's a constitutional issue: https://assets.documentcloud.org/documents/3437026/Darweesh-...

"The petitioners have a strong likelihood of success in establishing that the removal of the petitioner and others similarly situated violates their rights to Due Process and Equal Protection guaranteed by the United States Constitution"

It's a constitutional issue in every sense. The US Congress ALONE has the power to make policy. The POTUS can relax policy enforcement, but cannot enforce policy that was never made. What part of this is hard for you to understand??

Where did you get from? That's 100% wrong. The power to determine who is admissable to the US lies in the hands of the president when it comes to the security of the country.