It has now been several weeks since President Trump suggested sending illegal aliens to so-called sanctuary cities, and long past due to acknowledge his brilliance in setting the terms of the political debate on this and other issues.

“Due to the fact that Democrats are unwilling to change our very dangerous immigration laws, we are indeed, as reported, giving strong considerations to placing Illegal Immigrants in Sanctuary Cities only,” Trump tweeted on April 12. “The Radical Left always seems to have an Open Borders, Open Arms policy — so this should make them very happy!”

Of course, it did not make them very happy, or even remotely happy. It made them mad, which was its true purpose. More importantly, it made them face the hard consequences of their easy political posturing on illegal immigration. Put another way, President Trump was making the left live up to its own immigration rule book.

If that sounds familiar, it’s because it is a paraphrase of Saul Alinsky’s Rule No. 4: "Make the enemy live up to its own book of rules."

Democrats have been using Alinsky's "Rules for Radicals" effectively for years to keep Republicans off balance. A Chicago political activist who died in 1972, Alinsky was the godfather of community organizing and the inspiration for progressive Democrats such as Barack Obama and Hillary Clinton. For Republicans’ part, although always aware that Alinsky’s rules worked, they were afraid to adapt them for their own use because they were afraid of the word "radical."

That's actually a demonstration of Rule No. 3: "Whenever possible go outside the expertise of the enemy." Republicans are stuffed-shirt conservatives, remember? They won't do anything radical; that's just for the progressive left!

At least, until Donald J. Trump changed politics forever in the 2016 presidential campaign. Indeed, as we study President Trump’s winning strategy in that election and his governing strategy in the years since, it becomes clear that the New York billionaire is a devoted student of the Chicago community organizer. From now on, indeed, we are justified in talking about Trump’s “Rules for Republicans,” as adapted from Alinsky. If other GOP politicians shy away from the formula that Trump has perfected, they do so at their own risk.

In his prologue to “Rules for Radicals,” Alinsky made it clear that his book is about “the art of communication” and that the rules he enunciated don’t just work for radicals who want to tear down the system, but for any radicals “who want to change their world.” That, in sum, is exactly who Donald Trump is, and exactly why the Deep State and the Enduring Bureaucracy fear him. Trump understood innately the truth of Alinsky’s theorem that:

“... there are certain central concepts of action in human politics that operate regardless of the scene or the time. To know these is basic to a pragmatic attack on the system. These rules make the difference between being a realistic radical and being a rhetorical one who uses the tired old words and slogans…”

In this light, let’s consider that tweet about sanctuary cities again. Not only does it make Democrats live up to their own “open borders” rule book, it also demonstrates the truth of Alinsky’s Rule No. 9: "The threat is usually more terrifying than the thing itself."

Democrats scurried every which way to run for cover in the wake of Trump’s threat. More importantly, there actually has been some significant movement toward the president’s point of view in the last three weeks. To the shock of many, New York Times columnist Thomas Friedman wrote on April 23 that he was “more certain than ever that we have a real immigration crisis and that the solution is a high wall with a big gate — but a smart gate.”

Friedman’s “smart gate” option was a virtual recapitulation of Trump’s border policy in prettier words:

“Besides legitimate asylum seekers, we’ll accept immigrants at a rate at which they can be properly absorbed into our society and work force, and we’ll favor visa seekers with energies and talents that enrich and advance our society.”

Friedman’s home newspaper could not quite bring itself to support the wall, but it did publish an editorial on May 5 that called on Congress to “Give Trump His Border Money.” Although somehow the editorial board of the Times could not sniff out a national security threat in the current flow of uncontrolled immigrants across the border, it was able to sense that hundreds of thousands of impoverished asylum seekers could indeed overwhelm our national resources, and maybe even the noble intentions of our sanctuary cities.

The most convincing proof of Trump’s ability to sway the argument came from an unexpected source: the superannuated pop singer Cher, who wrote on her own Twitter account this raw plea to the president not to drop illegal immigrants into Los Angeles:

"I Understand Helping struggling Immigrants,but MY CITY (Los Angeles) ISNT TAKING CARE OF ITS OWN.WHAT ABOUT THE 50,000+Citizens WHO LIVE ON THE STREETS.PPL WHO LIVE BELOW POVERTY LINE,& HUNGRY? If My State Can't Take Care of Its Own(Many Are VETS)How Can it Take Care Of More?"

Whoa! Sounds like the liberal Democrats who run Los Angeles and California aren’t living up to their own rule book on a whole host of issues! Thanks, Cher, for proving the president’s point.

As for the rest of the “Rules for Radicals,” not each of them has been used by President Trump yet, but several of them are so central to his public persona that it can’t be accidental.

Trump is master of rule No. 5, for instance: “Ridicule is man’s most potent weapon.” If you don't think so, just ask Low Energy Jeb Bush or Crooked Hillary Clinton.

And when it comes to rule No. 6, you can be sure that President Trump understands that "A good tactic is one your people enjoy." Candidate Trump used to try out ideas at his rallies and would stick with the ones that got a positive reaction. Thus “Build that wall” and “Drain the swamp” became central components of Trump’s winning campaign because he recognized the power of jubilation.

What about rule No. 8 — “Keep the pressure on”? The Fake News Media can certainly attest to the fact that Trump is a master of this one, too. In the case of Sen. John McCain, Trump has proven he will keep the pressure on even after his nemesis is dead.

That brings us to rule No. 13, a summation of the entire Trumpean political ethic and an explanation for why he cannot easily be defeated: "Pick the target, freeze it, personalize it, and polarize it." You can go through the rogues’ gallery of Trump’s targets and nary a one of them has come through the experience unscathed: Jeb, Hillary, McCain, CNN, NATO, illegal immigrants, Congress, Democrats, Michael Cohen, Bob Mueller, Liddle Bob Corker, Leakin’ Lyin’ James Comey, Little Rocket Man, or (my personal favorite) George “Mr. Kellyanne” Conway.

President Trump always told us he was a counter-puncher; he just never revealed that his cornerman was the patron saint of liberals, Saul Alinsky. It shouldn’t have come as a surprise though. After all, they are both community organizers; it’s just that Trump set his sights a little higher.

Welcome to MAGA country.