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Pandering politicians regularly insist that undocumented immigrants are a danger to society.

"They're bringing drugs. They're bringing crime," Donald Trump famously declared in announcing his candidacy for president. A decade earlier, Iowa congressman Steve King said 13 Americans die each day as a result of undocumented drunk drivers.

A just-released study suggests such claims are hacia atrás—exactly backwards. Looking at state-level data, it finds three major drug-related problems are apparently mitigated as the population of undocumented immigrants grows.

Specifically, states with an increasing concentration of non-citizen residents lacking proper papers experienced "reductions in drug arrests, drug overdose deaths, and DUI arrests," writes a research team led by sociologist Michael Light of the University of Wisconsin–Madison.

"There are good theoretical reasons to think (an influx of undocumented immigrants) could have increased substance abuse problems in recent decades," Light said in announcing the results. "But the data just doesn't show it."

The study, published in the American Journal of Public Health, examined data from 1990 to 2014. The undocumented immigrant population of each state—and the percentage of the total population it represented—was provided by the Center for Migration Studies and the Pew Research Center.

"Undocumented persons may be less likely to drive after drinking, or drive at all, because of fear of police surveillance and deportation."

Data on arrests for DUI and drug crimes was provided by the Federal Bureau of Investigation; alcohol-related traffic accident facilities were compiled by the National Highway Traffic Safety Administration.

Crunching the numbers, the researchers found a 1 percent increase in the proportion of a state's population that is undocumented is associated with 22 fewer drug arrests, 0.64 fewer drug-overdose deaths, and 42 fewer DUI arrests for every 100,000 people.

While the reasons for this correlation weren't investigated, Light and his colleagues offer several possible explanations. "Undocumented persons may be less likely to drive after drinking, or drive at all, because of fear of police surveillance and deportation," they write. "For similar reasons, they may socialize and drink primarily within immigrant enclaves, obviating the need to drive."

They further note that "undocumented immigrants are often motivated by economic opportunities for themselves and their families." This drive might "predispose them to less criminal involvement, and healthier behaviors."

"Our study does not contradict assertions that drugs are smuggled across the U.S. border (they are), or that individual undocumented immigrants have been arrested for drunk driving," the researchers conclude.

"Our findings do, however, significantly undermine arguments that the public is at greater risk for DUI or drug problems as a result of undocumented immigration. If anything, they suggest the opposite."

Still no word, however, on how one's driving is affected by having calves the size of cantaloupes.