Donald Trump’s immigration policy is loaded with exaggerations.

Donald Trump’s immigration plan is loaded with exaggerations and untruths.

“They have to go.” That’s the bottom line for Donald Trump as he appeals to the nativists among us who would seriously consider his so-called plan to fix America’s immigration problems.

Under a President Trump, some 11 million immigrants without proper documentation would be rounded up and shipped out of the country, despite the fact — and, yes, facts do matter — that such a cruel deportation scheme would cost at least $100 billion, according to most estimates, and would take years to complete. A 2010 study by the Center for American Progress estimated that the United States would need to spend at least $285 billion over five years to deport all 11 million immigrants in the country illegally, roughly the population of Ohio. The process would involve detaining them for an average of 30 days, legally processing them and transporting them back to their birth countries.

Family members, even those who are citizens, likely would go too, since the ever-caring candidate prefers to keep families together. Never fear, though: He would let “the good ones” back in.

Imagine the economic upheaval, the human suffering and the community disruption that mass deportation would ignite, particularly in light of the fact that more than 60 percent of the undocumented have lived in this country for at least a decade. The vast majority are stable, productive members of society, as Houstonians and most Americans are well aware. Imagine the harassment and discrimination that would become part of everyday American life as immigration agents go looking not just for the undocumented but also for anyone whose legal status might be suspect.

Trump calls for ending “birthright citizenship,” the right established by the 14th Amendment to the Constitution and upheld by the U.S. Supreme Court for more than a century. He claims that birthright citizenship is a seductive magnet for the undocumented — the old “anchor baby” argument — but again the facts belie the claim. Study after study has found that immigrants without documentation come to this country to work and to provide for their families, not to give birth to new American citizens.

Trump wants to build a 2,000-mile border wall and get Mexico to pay for it. He has no sense of the deep and abiding ties — economic, social and cultural— that bind Mexico and the U.S., no sense of the disruption a massive wall would cause, no awareness of the cost. He would spend billions to fix a perceived problem that doesn’t exist. We already have spent billions on border enforcement in recent years, and the border has never been more secure. Illegal crossings are at their lowest level in two decades.

Trump’s plan is loaded with similar misleading claims, contradictions, exaggerations and outright untruths, and yet Republican voters tell the pollsters they’re all for it. That’s disturbing.

It’s tempting to dismiss the billionaire developer/TV showman as a bar-stool blowhard mouthing off on issues he knows nothing about — “Hey fellas, listen up! This ol’ boy’s spent half a day in Laredo!” — but as he stays atop the Republican presidential polls he can’t be ignored. He’s tapping into a dark and dangerous strain of nativist anger and resentment that represents our nation’s worst instincts. Like a herpes virus, it’s always lurking in the body politic, but only erupts now and then. Trump’s presidential campaign has come to embody that virus.

His GOP competitors are trembling like spring lambs. None of them have dared call him out for proposing a plan that scapegoats immigrants, damages the economy and wastes billions of dollars. Wisconsin Gov. Scott Walker, in particular, is scrambling to sound as hard-nosed as the faux-populist frontrunner and is making himself look foolish in the process. Although he called for a pathway to citizenship for the undocumented just a couple of years ago, he now allows that his immigration ideas are “very similar” to Trump’s. He too wants to build a wall, and, like Trump, he wants to “end the birthright citizenship problem.”

Walker’s not the only one blown over by the bloviator-in-chief. South Carolina Sen. Lindsey Graham, New Jersey Gov. Chris Christie, former Pennsylvania Sen. Rick Santorum and Louisiana Gov. Bobby Jindal also have decided they want to repeal birthright citizenship, and Dr. Ben Carson is calling for armed military drones at the border. Former Florida Gov. Jeb Bush and Florida Sen. Marco Rubio, both experts on immigration reform, seem reluctant to engage him.

Immigration reform and border integrity are legitimate issues as the presidential campaign unfolds, but when the proposal on the table is an exercise in xenophobia, racism and cruelty, we have a bigger problem that needs addressing than illegal immigration.