Both Republican presidential candidate Donald Trump and conservative pundit Ann Coulter have warned about violent crime by undocumented immigrants.

 “When Mexico sends its people, they’re not sending their best. They’re not sending you. They’re not sending you. They’re sending people that have lots of problems, and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.”

— Donald Trump, June 16

These were among the most controversial lines from Donald Trump’s presidential campaign announcement. The real-estate developer did not back down from the remarks, despite a backlash from Latino leaders and from corporate partners such as Univision, Macy’s and NBC, which severed various business relationships with Trump. “What can be simpler or more accurately stated?” Trump said in a July 6 statement defending his remarks. “The Mexican government is forcing their most unwanted people into the United States. They are, in many cases, criminals, drug dealers, rapists, etc.”

Trump’s confidence may have been bolstered by a new book from bestselling conservative firebrand Ann Coulter. In “Adios, America: The Left’s Plan to Turn Our Country Into a Third World Hellhole,” Coulter devotes three chapters — and three “Spot the Immigrant!” case studies — to recounting cases of rape and sexual assault involving undocumented immigrants, many of them from Mexico and throughout Central America. “America is just bringing in a lot of rapists,” she warns.

The book, which has earned a spot on both the New York Times and Washington Post nonfiction bestseller lists, was published June 1, more than two weeks ahead of Trump’s announcement. Via e-mail, Coulter told me that Trump had “asked for, and received, an advance copy of my book, and he told me. . . that he’s read the book cover to cover.” She emphasized that Trump has “been talking about immigration for years. . . he didn’t get his ideas from me. He had them. My book supports his ideas.”

In his 2011 book, “Time to Get Tough,” Trump expressed concerns over crimes committed by immigrants who had entered the United States illegally. “I actually have a theory that Mexico is sending their absolute worst, possibly including prisoners, in order for us to bear the cost, both financial and social,” he wrote.” This would account for the fact that there is so much violence and crime.” He did not mention rape then, instead citing fatal drunk-driving incidents and other offenses, as well as activities by Central American gangs in the United States. “Obviously not all illegal immigrants are members of violent gangs,” Trump added. “Many aliens are just seeking a better life for their families.”

In late May, Trump was already tweeting his admiration of Coulter’s book, as Eric Hananoki of Media Matters has pointed out.

Members of the Trump team did not respond to repeated e-mails asking to what extent Coulter’s book had helped shaped his views on immigration. In a July 23 e-mail to Coulter, Trump senior political adviser Corey Lewandowski assured her that “Mr. Trump loves you. You know that.” (I was cc’d on the message.)

Coulter has been outspoken in her support of Trump, calling his views on immigration “fantastic” and jokingly volunteering to run the Department of Homeland Security in a Trump administration. And in an interview with New York magazine, she noted that “nobody talked about Hispanic child-rape until now. That was in his opening speech!”

On July 8, The Washington Post’s Fact Checker column assessed Trump’s statement connecting immigration and crime as false, awarding it the harshest rating of four Pinocchios — reserved for “whoppers.”

(This post has been updated.)

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