They have repeatedly taken incredibly broad if not downright delusional interpretations of legal precedent and used them to set policy. They literally tried to override a constitutional amendment (birthright citizenship) with an executive order. They have been laughed out of court many times but have won a shocking number of these ridiculous cases. This is just another one. Set the maximal policy that they want and make their opponents challenge it in court. It's legal until someone (with standing) stops them.
Read the law! It’s there in black and white! It’s 8 USC 1101(a)(15) and (a)(15)(H). It’s a “nonimmigrant” visa for people “temporarily” in the U.S. https://www.law.cornell.edu/uscode/text/8/1101
How is it “delusional” to interpret a law that’s plastered with the words “non immigrant” and “temporary” and say that maybe it shouldn’t be a de facto path to permanent residency?
H1b (the visa status of nearly everyone here affected by this change) is only 36 years old. We're not talking about ancient case law here.
Trying to follow the Constitution literally is hard and in practice, it's not done. The political system just interprets the Constitution in whatever way the consensus of the given moment wants to interpret it. The 14th Amendment is clear that all persons born in the US are citizens of the US. However, if you follow the 2nd Amendment just as literally, it means that the Federal government, at least, cannot make any laws restricting us from owning nuclear weapons.