"Not one of the stalwart liberals on the Supreme Court, including Justice Ginsburg, Justice Sotomayor, Justice Kagan, and Justice Breyer could bring themselves to agree with any of the lower court rulings enough to even write a dissent to this decision and push for keeping the stays in place."

So how did the lower courts get away with that? The majority of the judges in those cases struck down the Trump travel ban based on statements then-candidate Trump made about wanting at least a temporary "Muslim ban" on entry into the U.S. The decisions referred to those comments as evidence that the travel ban was not an example of a constitutional executive power, but was the product of an illegal discriminatory practice.

That meant that if the very same travel ban had been imposed by President Obama, the same court would have upheld it as legal. And as legal scholar Alan Dershowitz said at the time: "In my view, that is a bridge too far. It turns constitutional analysis into psychoanalysis, requiring that the motives of the president be probed." That kind of scrutiny is not what the Constitution calls for in its separation of powers clauses. And it's encouraging that someone like Dershowitz, who still opposed the ban on policy grounds, had the great integrity to point this out publicly.

It should be noted well that Monday's Supreme Court decision disagreed with the immediate alarm the lower courts assigned to the arguments about due process and President Trump's true intent, and let the ban go into effect until at least October when the justices will hear the case in full. Thus, the only slightly-modified travel ban was just allowed by what amounts to a unanimous decision. Only the three most conservative justices on the court wrote that they think the ban should be upheld in its entirety.

Think about that for a second. Not one of the stalwart liberals on the Supreme Court, including Justice Ginsburg, Justice Sotomayor, Justice Kagan, and Justice Breyer could bring themselves to agree with any of the lower court rulings enough to even write a dissent to this decision and push for keeping the stays in place. That just shows how far to the left some of the federal courts have become in America.

Now for the dicier question: Will this ban actually make us safer? It's true that refugees and and immigrants from the banned countries haven't spawned a rash of terrorist attacks in the U.S. However, it was a Somali refugee who plowed into people and then went on a stabbing spree at Ohio State University last November. And no police or military force worth its salt is only concerned about who has carried out attacks in the past. All of us expect some level of protection from plausible future attacks. What's going on in Europe and what happened last year at Ohio State provide plenty of credibility for guarding better against this threat.

Hopefully, none of us will even have to find out exactly how many lives are endangered when these kinds of travel bans aren't in effect. But what we do know is that the Trump team and established U.S. immigration law both won major victories that will at least provide the nation needed clarity for years to come.

Commentary by Jake Novak, CNBC.com senior columnist. Follow him on Twitter @jakejakeny.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.