The courts disagree, and I don't mean the 9th Circuit. Constitutional due process rights apply to everyone in the country, not just citizens. Aliens outside the country have no constitutional rights. Everyone inside does. Disagree with that if you like, but argue with the courts, not me.
Green Card holders are here on an immigrant visa - once they leave the country, they are subject to reentry requirements. They are not “in country” and are not citizens -> no due process as a “right” is not being denied.
A Green Card *may* grant then some privilege not available to other immigrants, but they are still subject to immigration procedures.
One of those privileges might be that you can not be sent back directly and can retain counsel and apply for a waiver for the disqualifying factor. That privilege was NOT abridged in the EO, if it exists at all.
Again, travel outside the US is voluntary - if you decide to leave, for whatever period and whatever length, you are subject to re-entry regulations. The Regulation states “all classes” of immigrant and nonimmigrant. IOW the President CAN deny Green Card holders (a class of immigrant) at his discretion and for as long as he deems necessary, re-entry into the US. He can NOT, by decree, revoke the Green Card or the Visa. He was not granted that power.
The law is clear and concise and INCLUDES Green Card Holders if the President so decrees.
Don’t give an inch on that argument. The courts to NOT agree - this is settled law that is simply being ignored.