The biggest surprise so far in the 2016 presidential campaign is the support for billionaire developer Donald Trump. Polls show him leading the Republican nomination race, with the backing of about 18 percent of respondents.[1] Granted, that’s roughly the same percentage that distant-second Bernie Sanders is drawing on the Democratic side,[2] so one of the reasons for Trump’s frontrunner status is the crowded GOP field.

But another reason is the appeal of his message, and who it’s appealing to. Polls show his supporters typically are not aligned with the traditional GOP base groups;[3] his backers are more likely than other Republicans to identify as moderate or liberal and less likely to identify as very conservative or evangelical.[4] Meanwhile, social conservatives, small-government types, and business Republicans are gravitating toward other GOP candidates.

Trump backers are also more likely to be young, less likely to have a college degree, and about evenly distributed between men and women.[5] So why does he appeal to those people?

His chief stump issues are the economy and immigration. It’s easy to see why, after the last eight years, Trump’s promise of an economic resurgence would appeal to younger adults. And if non-degreed supporters see immigration as a threat to their jobs and wages, he would be even more appealing.

But on immigration, candidate Trump and his supporters overlook something that businessman Trump (a mega-developer and hospitality industry titan) likely understands well. Call it the Golden Rule of Immigration: People who come to America to work hard and make an honest living are good for the nation. They provide more hands, more skills, and more brain power to produce American food, build American homes, provide Americans with services, form American businesses and create future American goods.

Trump supporters might disagree, arguing that immigrants don’t produce economic growth, but rather take jobs away from native-born workers and reduce wages. Interestingly, Sanders criticizes immigration for this same reason.[6] But economic data show otherwise. The inflow of high-skilled immigrants—scientists, engineers, computer techs, doctors, architects, etc.,—have been shown to boost wages for native-born workers.[7] That makes sense; those immigrants’ rare and valuable talents are the sort that fuels innovation and boosts job creation.

Even low-skilled immigrant workers seem to have a positive—or, at least, not a negative—effect on native-born Americans’ jobs and wages. These immigrants often serve as support staff for native workers, making the natives more productive and therefore more valuable employees. However, the economic research does show that immigration does harm some workers: specifically, those with few job skills and no high school diploma (and who, in many cases, are previous immigrants).[8] On the other hand, immigration appears to encourage at-risk natives to stay in school, which boosts their economic prospects.[9]

On balance the economic data support the Golden Rule: immigration benefits the national economy and native workers as a group.

Trump supporters might respond that there are more concerns than economics; immigration threatens public safety. Trump himself said of “Mexican” immigrants: “They're bringing drugs. They're bringing crime. They're rapists." And some high-profile, immigrant-committed crimes have been in the news lately. But criminal justice research indicates that immigrants are much less likely than native-born Americans to commit a violent crime or be imprisoned.[10] This is true, also, of the “Mexican” immigrants Trump specified.

His supporters would likely reply that millions of immigrants have committed a crime: entering the country illegally. And, they’d add, they don’t oppose immigration, just illegal immigration. Why can’t illegals follow the rules and enter the country legally, allowing government officials to investigate them to ensure they’re not threats to public safety? On this, they have a point.

Here’s the rub: the U.S. immigration process is a legal and bureaucratic mess. If a foreigner is an immediate family member—a minor child, spouse, or parent—of a legal American resident, the process moves fairly quickly (for government), taking perhaps six to 18 months. For very high-skilled workers—say, people with advanced degrees—who already have a job lined up, the process is also fairly quick—perhaps 18 months, though in some cases even less.

But others face a much longer wait. For regular workers with jobs already lined up, the process can take several years. As for the ordinary foreigner with no legal problems but no immediate U.S. family member and no job lined up, who simply wants to come to America to work hard and make an honest living, the wait time varies between many years and never.[11]

That’s not only bad for immigrants, but for America. If the nation wants to fix its illegal immigration problem, it first needs to fix the mess that is legal immigration. And we—and the next president—should want to do this. Because, again, the Golden Rule of Immigration: people who come here and work hard to make an honest living are good for America.

Thomas A. Firey is a senior fellow with the Maryland Public Policy Institute and a Washington County native.