Nobody knows where Donald Trump will stand six months from now in this bizarre Republican presidential campaign. 

But you can predict with some confidence how his recent anti-Muslim diatribes will look in a decade or two, unless Trump manages to rewrite the Constitution itself. 

American politics, like most things, is a story of what statisticians describe as the reversion to the mean. Self-proclaimed saviors and other outliers come and go throughout our political history. Occasionally they’re successful; most times, they’re not. But the system has rebalanced toward the basic principles of tolerance, freedom and democracy that were set forth by the Founders. 

This inner balance wheel is one reason that Warren Buffett, our most brilliant modern business tycoon, likes to say that no matter how severe an economic downturn may seem, investors have never made a mistake betting on the ability of the American system to recover. This mysterious engine of creativity and self-correction could finally be broken after 226 years, but I doubt it. 

Trump’s anti-Muslim rhetoric will live in infamy in American history. He obviously doesn’t mind; his narcissistic personality is so extreme that every high-visibility outrage is for him a kind of validation. (If you’re curious about other examples of such personalities, read the recent book “Narcissism and Politics: Dreams of Glory,” by Jerrold Post, the CIA’s former director of psychological profiling.)

But the judgment of history should matter to other Republicans. Historians will look harshly on those who, for reasons of cowardice or opportunism, kept silent when Trump’s tirades put our constitutional values and the safety of Americans at risk — not to mention the political future of the GOP. 

House Speaker Paul Ryan offered the simplest and most direct rebuttal on Tuesday, the day after Trump called for a ban on Muslims entering America: “This is not conservatism. What was proposed yesterday is not what this party stands for, and more importantly, it’s not what this country stands for. 

Not only are there many Muslims serving in our armed forces dying for this country, there are Muslims serving right here in the House, working every day to uphold and to defend the Constitution.”

Ryan gets my “Have You No Sense Of Decency, Sir” award, named for the famous rejoinder by Boston lawyer Joseph Welch, who called out the reckless anti-communist crusader Sen. Joseph McCarthy in the 1954 Army v. McCarthy hearings. Those seven words began the reversion to the mean after the Red Scare.

People will play the Ryan video clip decades from now when they want to understand when America began to regain its balance. Ryan temporized about whether he would support Trump if he’s the GOP nominee, but Ryan surely can’t endorse a candidate whose proposals “are not what our country stands for.”

How will history judge other prominent Republicans who have been onlookers and even cheerleaders as the Trump car wreck ensued? Can Sen. Ted Cruz really continue to waffle on anti-Muslim statements? Is this former Supreme Court law clerk really so clueless about the Constitution? 

How about Sen. Marco Rubio? Does he have the backbone to take on the demagogue? All we can say is that historical reputations will be made and lost over the next few weeks.   

It’s not hard to imagine what James Madison or Thomas Jefferson or Alexander Hamilton would have made of Trump. He’s a populist bully — the type of impulsive, autocratic political leader that the Constitution and Bill of Rights were intended to guard against. The framers hated the tyranny of King George, but they were also afraid of the mob. That’s why they put so many checks and balances into our system, to guard against the excesses of a government that might be inflamed by public passion or perverted by a dictator’s whim. 

In the end, America will get the leadership it deserves, and that may include Trump if he stays popular. Sometimes good countries are so traumatized by events that they lose their bearings and embrace bad leaders. 

A clever politician can galvanize a shattered people’s rage and national pride — in the way that a Napoleon did after the French revolution, or Adolf Hitler and Benito Mussolini did with the war-ravaged middle class of Germany and Italy. 

Watching Trump supporters vent their fear and anger, no one would say that it can’t happen here. The mood among Trump’s followers is as ugly as his rhetoric. But history tells us that the demagogic wrecker probably won’t succeed here. And if he does, it won’t be for long.

By David Ignatius

David Ignatius’ email address is davidignatius@washpost.com. — Ed. 

(Washington Post Writers Group)