One of the toughest questions I received during my book tour for “The Corrosion of Conservatism: Why I Left the Right” came from a high school student who asked how she could trust anything I said now that I had disavowed my previous beliefs.

I replied that this was an exaggeration. I still believe in most of the things I always did — free trade, immigration, human rights, fiscal responsibility, a strong defense, standing up to dictators, supporting American allies, holding the president to a high standard. It was the Republican Party that changed — not me.

But it is true that I’ve rethought my views on some important matters, such as the Iraq War, and started speaking out on issues such global warming, gun control and white privilege where reality conflicts with conservative dogma. “You can trust me now,” I said, “precisely because I have changed my mind. Don’t trust anyone who hasn’t.”

Which brings me to Bernie Sanders, who never seems to have changed his views about anything. This is a big selling point for the controversial podcaster Joe Rogan, who endorsed Sanders by praising him for being “insanely consistent his entire life.” I can’t imagine a worse indictment. It means that Sanders is captive to a rigid ideology that he has never bothered to rethink, even though the world has changed beyond all recognition since he was born a few months before the Japanese attack on Pearl Harbor.

Sanders’s record indicates that there are a lot of views he should revise — in particular his romantic infatuation with Communist movements. In the 1980s, as mayor of Burlington, Vt., Sanders opposed the U.S. invasion of Grenada, which toppled a Communist regime, and U.S. support for the government of El Salvador, which prevented the Communist FMLN guerrillas from coming to power.

Fair enough. But Sanders didn’t stop there. In 1985, he traveled to Nicaragua to celebrate the sixth anniversary of the Sandinista takeover. He told a state-controlled newspaper: “After many years of economic and political domination, Nicaragua is determined not to be a banana republic anymore, and it’s free to make its own decisions. Is this a crime?” There was no hint of reproach in his remarks for the serious human-rights abuses committed by the Sandinista dictatorship. He even echoed Communist propaganda by calling American reporters “worms” for publishing articles critical of the regime.

Three years later, in 1988, Sanders took a “romantic” honeymoon trip with his bride to the Soviet Union. “As he stood on Soviet soil,” The Post reported last year, “Sanders, then 46 years old, criticized the cost of housing and health care in the United States, while lauding the lower prices — but not the quality — of that available in the Soviet Union. Then, at a banquet attended by about 100 people, Sanders blasted the way the United States had intervened in other countries, stunning one of those who had accompanied him.” This was at a time when even Soviet leaders had realized their country had fallen hopelessly behind the United States both economically and politically — and while the Red Army was withdrawing from Afghanistan.

In 1989, Sanders visited Cuba, another impoverished and tyrannical Communist regime, and came back with a glowing report. “Under Castro, enormous progress has been made in improving the lives of poor people,” Sanders said before leaving. Upon returning home, he told the Burlington Free Press: “I did not see a hungry child. I did not see any homeless people.” While Cuba was “not a perfect society,” he said, the country “not only has free health care but very high-quality health care. … The revolution there is far deeper and more profound than I understood it to be. It really is a revolution in terms of values.”

Play the Post Opinions Simulator to see what might happen in the Democratic primary.

None of this means Sanders was a Communist. It does mean he was hopelessly naive. Yet when called out by the New York Times last year on his foreign policy views, Sanders was positively Trumpesque in his lack of contrition. “I was right about Vietnam. I was right about Iraq. I will do everything in my power to prevent a war with Iran. I apologize to no one,” he tweeted.

Sanders would be more credible and convincing if he would recant his earlier illusions. He should then rethink his more recent support for the toppled leftist leader Evo Morales in Bolivia and his opposition to President Trump’s attempts, in cooperation with U.S. allies, to topple the repressive Maduro dictatorship in Venezuela.

I have more respect for Elizabeth Warren, who advocates many of the same progressive policies as Sanders but is not as supportive of far-left leaders abroad. Perhaps that’s because Warren herself was once a Republican. She changed her views as an adult because her study of bankruptcy laws led her on an intellectual journey to the left. It’s too bad that Warren so seldom talks about her conservative past because it shows she is capable of adjusting her conclusions in light of changing facts. Sanders, by contrast, discredits himself by falling prey to the “foolish consistency” that Ralph Waldo Emerson called “the hobgoblin of little minds.”

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