Fact-checking Donald Trump: How he gets a lot of things wrong.

Billionaire developer and reality TV personality Donald Trump has been getting the cold-shoulder treatment from the Republican establishment, especially most of the other presidential hopefuls, for his controversial remarks about immigration.

But the veracity of his assertions – not just on immigration but on a wide range of issues – is being tested by fact-checkers as well.

In a blistering op-ed piece about the reemergence of anti-immigration thought similar to the Know Nothing movement of the 19th century, Timothy Egan of The New York Times takes on Trump and conservative political commentator Ann Coulter, whose latest book is titled  “¡Adios, America! The Left’s Plan to Turn Our Country Into a Third World Hellhole.”

Egan points to a Pew Research Center report concluding that “the net migration flow from Mexico to the United States has stopped and may have reversed.”

According to Pew, “The standstill appears to be the result of many factors, including the weakened U.S. job and housing construction markets, heightened border enforcement, a rise in deportations, the growing dangers associated with illegal border crossings, the long-term decline in Mexico’s birth rates and broader economic conditions in Mexico.”

Egan also cites National Bureau of Economic Research data showing that “poor immigrants are less likely to take advantage of free government help than citizens.”

As for Trump’s controversial remark about many Mexican immigrants being violent criminals, including “rapists,” that too is questionable. (“They’re bringing drugs,” Trump said in announcing his presidential bid last month. “They’re bringing crime. They’re rapists.”)

“The Congressional Research Service found that the vast majority of unauthorized immigrants do not fit in the category that fits Trump’s description: aggravated felons, whose crimes include murder, drug trafficking or illegal trafficking of firearms,” The Washington Post reports. “CRS also found that non-citizens make up a smaller percentage of the inmate population in state prisons and jails, compared to their percentage to the total U.S. population.”

Based on an analysis of data from the FBI, the US Census Bureau, and other agencies, the American Immigration Council reports:

“A variety of different studies using different methodologies have found that immigrants are less likely than the native-born to engage in either violent or nonviolent ‘antisocial’ behaviors; that immigrants are less likely than the native-born to be repeat offenders among ‘high risk’ adolescents; and that immigrant youth who were students in U.S. middle and high schools in the mid-1990s and are now young adults have among the lowest delinquency rates of all young people.”

While Trump’s incendiary comments about immigrants have gotten the most attention, his rhetorical forays into military policy and national security have triggered pushback as well.

In order to defeat ISIS, Trump says he would “bomb the hell” out of oil fields in Iraq.

"If I win [the presidential election], I would attack those oil sites that are controlled and owned – they are controlled by ISIS," Trump said. "I wouldn't send many troops because you won't need 'em by the time I'm done."

Military experts say that would do more harm than good, CNN reports, because it would make it more difficult for Iraq to rebuild once ISIS is defeated.

"You're destroying the infrastructure of Iraq, you're not really doing much to hurt ISIS," retired Lt. Col. Rick Francona said. "At some future point those oil fields will have to help regenerate Iraq."

"You have to understand the issues a little bit better than just bombing things," says Lt. Gen. Mark Hertling, another CNN military analyst.

Cynics may believe that “truth in politics” can never be firmly established. But a number of institutions and organizations give it a try, including Pulitzer Prize winner PolitiFact, an independent fact-checking journalism website. Here’s how they grade 23 of Donald Trump’s statements: Two are true; three are half true; two are mostly false; ten are false; and six are “pants on fire.”

Among the Trump statements rated false are those having to do with public approval rates on abortion, the US unemployment rate, the enrollment rate for the Affordable Care Act, the amount President Obama has spent defending lawsuits regarding his birth certificate, the reliability of the US nuclear arsenal, whether South Korea pays for US troops based there, who buys Libyan oil, and the fact that his book “The Art of the Deal” is “the number one selling business book of all time.”

PolitiFact also debunks several Trump statements on immigration.

For his questionable and downright false assertions about immigration, the Post’s fact-checker feature awards Trump “Four Pinocchios,” defined as “Whoppers.”

“Trump’s repeated statements about immigrants and crime underscore a common public perception that crime is correlated with immigration, especially illegal immigration,” writes the Post’s Michelle Ye Hee Lee. “But that is a misperception; no solid data support it, and the data that do exist negate it. Trump can defend himself all he wants, but the facts just are not there.”

Meanwhile, most Republicans are distancing themselves as rapidly as possible from Trump’s comments on immigration.

On Saturday, Trump is scheduled to speak to an event at the Phoenix Convention Center hosted by the Republican Party of Maricopa County and featuring Sheriff Joe Arpaio, another outspoken opponent of most immigration.

US Sens. John McCain and Jeff Flake and Gov. Doug Ducey, all Republicans, are shunning the event, reports The Arizona Republic.

"Donald Trump's views are coarse, ill-informed and inaccurate, and they are not representative of the Republican Party," said Sen. Flake."As an elected Republican official, I'm disappointed the county party would host a speaker that so damages the party's image."

In addition to the media sniping and fact-checking watchdogs, Trump has seen some of his many business ties broken as a result of his comments on immigration. Does he care about any of this? Apparently not.