Couple things.If this has been asked and answered I apologize. My question is why is Trump's executive order unconstitutional ? That seems to be the question before the 9th court. As I understand it only those without valid citizen status, passports, or visa are restricted for 90 days. Those critical state his is a Muslim ban and don't seem to mention anything about the 90 day portion of the restriction. Why is that ?
First, the actual text of the EO is significantly broader and would appear to apply to any non-citizen traveling from the 7 countries. That would include people who already have a vested interest in being here, like people with permanent resident status. That's the way it was initially enforced in certain ports of entry. That implementation is one part of what is being challenged. Trump's counterargument is that the EO was clarified to only apply to people without a vested interest (according to the DOJ). Part of the challenge is that the implementation was improper.
Second, a few of the states (WA, MN, and HI, I believe) are also challenging it on other grounds - that there is no rational basis for the action at all, and that it causes harm to residents (a lot of corporate residents) of their states. This is somewhat an extension of the first argument: that the residents, including corporations, had a right to rely on the prior implementation and the new implementation is not supported by the constitution.
As a secondary issue, when Obama and Congress passed the statute that basically listed the 7 countries at issue, no one challenged it. Some of the current challenges probably could've been brought when that was first enacted, but weren't. There's at least 1 challenge that the listing of countries discriminates against people based on "national origin" which is barred by several federal statutes, in different contexts. The executive is also bound to implement policies in conformity with laws. It is a "lesser" challenge than a constitutional one, but still a potentially valid argument.
We have many laws.