Trump has been doing many lawless things that the courts might theoretically put a stop to, but I'm not sure this is one of them. The text of 8 USC 1182(f) seems pretty straightforward:

> Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate.

It's a stupidly broad law, but Congress passed it, and now they're too dysfunctional to do anything about it. So I guess we're stuck with it.