It's a win in a case that should never have been brought to begin with.
The Supreme Court noted that President Trump has the legal authority to decide who enters this country. As every president before him was able to incontestably do based on the law and ample precedent. The travel ban that the left had been fuming about had been implemented to a lesser degree by Obama. (Much as with border separation, a policy that existed under Obama became outrageous under Trump) There was no serious legal argument to be made otherwise. And no serious argument was made.
The previous radical judicial activist decisions had tried to base themselves on President Trump's campaign trail statements.
The Supreme Court shot down that idea. It also shut down the notion of a First Amendment violation.
So it's a victory. And, for now, an inevitable one. Unlike some lower courts, the Supreme Court generally follows the letter of the law. Within limits. This decision was narrow. The court lefties rejected it. Which offers an ominous window into what would happen if they were to become a majority. And the decision itself was narrow and lacked any great enthusiasm for the subject.
That's part of the pattern with conservative victories in the Masterpiece cakeshop and Arlene's flowers cases.
When the left wins a Supreme Court decision, it wins big. Think gay marriage. But when the right wins a decision, it's smaller, narrowly interpreted and often lacks any passion for the subject.
In a way the voting cases that the Supreme Court ruled on were far more important because they established a meaningful authority for states to clean up the process.