The first point that Republican hopeful Donald Trump made in his victory speech after winning the April 19 primary in New York was that, as president, he would no longer allow U.S. jobs to be “sucked out” by Mexico. Obviously, Mexico-bashing still works for him.

The big question is whether his tirades against Mexico are part of a well-calculated populist campaign to appeal to the xenophobic feelings of angry voters, or whether he has a personal grudge against Mexico because of a bad business experience with a failed luxury condo project near Tijuana in 2009. It’s probably both, but definitely the latter is part of it.

Trump has put Mexico at the center stage of his presidential campaign since day one. On June 16, 2015, he launched his presidential campaign and made world headlines with his claim that most Mexicans are “rapists” and that they “bring drugs and crime.” Ever since, Trump has not stopped blaming Mexico for almost everything that is wrong in United States.

“Our jobs are being sucked out of our states, they are being taken out of our country,” he said in his New York victory speech. He vowed to “negotiate unbelievable trade deals, so we bring our jobs back, and we don’t let our companies go to Mexico and all of these countries anymore.”

Trump says he will slap a 35 percent import duty on Mexican goods, erect a wall on the Mexican border, deport 11 million undocumented immigrants and maybe cut Mexicans’ family remittances to their home country.

Thanks to Twitter, which Trump has compulsively used in recent years to opine about almost everything, we can assume that at least part of his anger at Mexico stems from his business fiasco with the Trump Ocean Resort luxury condo hotel project.

The three-tower, 25-story luxury Trump Ocean Resort Baja Mexico condo-hotel project by the Trump Organization and the Irongate real estate company was originally announced in 2006. Two years later, the project ran into financial trouble, and Trump removed his name from it. By 2009, the project was effectively suspended, and angry investors sued.

Trump said that he had merely licensed his name to the project, and had not been involved in building it. In November 2013, after more than four years of litigation, Trump — who often says, “I never settle lawsuits” — settled one lawsuit by about 100 would-be condo buyers, The Los Angeles Times reported at the time.

In a Twitter post on Feb. 24, 2015 Trump wrote, “I have a lawsuit in Mexico’s corrupt court system that I won but so far can’t collect. Don’t do business with Mexico!”

Can a candidate who tweeted “Don’t do business with Mexico!” shortly before he launched his presidential bid have an open mind about U.S.-Mexican ties?

It’s a fair question, especially considering Trump’s narcissistic personality, and the fact that every one of his immigration and trade charges against Mexico are based on half-truths or blatantly false data.

Trump tells his anxious audiences that the United States is being invaded by an avalanche of undocumented Mexicans. In fact, the flow of undocumented Mexicans to the United States has declined — yes, dropped — substantially since 2008, according to U.S. Census figures studied by the Pew Research Center.

Trump scares the public claiming that Mexico is “stealing” U.S. jobs, and that “we’re losing $58 billion a year” in trade with Mexico. But he hides the fact that about 40 percent of the content of U.S. imports from Mexico is of U.S. origin, according to a 2015 report by the U.S. Congressional Research Service.

My opinion: What’s especially troubling about Trump’s Mexico-bashing — and perhaps his entire foreign policy — is that it’s not based on what’s good for the country, but may be shaped by his business experiences.

This is not a man who has ever surrounded himself with foreign policy experts. In fact, he looks at them with disdain. As he told MSNBC’s Morning Joe March 16 when asked who he consults on foreign policy issues, “I’m speaking with myself, number one, because I have a very good brain.” He later added that “my primary consultant is myself.”

If Trump were a man who listened to others, this could change. But I’m afraid that a 67-year-old narcissistic billionaire with an authoritarian personality who publicly calls people who disagree with him “dummies,” “morons” and “losers” wouldn’t start listening to others overnight. Much less if he were emboldened by victory.