This isn't about the EPA.
From what I have read, it largely is the exact same thing. Washington state is arguing economic harm. Tech companies hire a lot of foreigners.
Constitutionality, Trump said he would favor one religion over another. That's a big no-no. I do like how the suit uses Trump's campaign words against him: if you say you are going to ban all Muslims, don't be surprised when someone believes it. I'm pretty sure that EPA lawsuit did the same with Obama and his words on coal.