Back in the middle of his campaign for president, Donald Trump outlined an immigration plan that would base more legal entries on merit, but it still came as a surprise to illiberal liberals when he recently said he was going to act on it.

What’s more, they were horrified, because, if we start searching for job skills, educated minds, entrepreneurial energy and that sort of thing that improves life for all, we will not be focused on saving the down and out. Isn’t that racist, nativist and jingoistic?

Well, no, because, the better-skilled may also be fleeing desperate circumstances and should hardly be denied our sympathy because, for instance, they’re better at English. And it’s also worth noting the current system of selection has been a disaster. Although a mix of many ideas, its main feature has been referred to as nepotism writ large: It extends special invitations to those who are relatives of citizens.

While all sorts of marvelous people have arrived under this plan (and the Trump plan will continue to give preferences to spouses and minor children), it has also become a means of importing poverty to the benefit of no one.

That phrase, “importing poverty,” has been used by particularly alert students of the subject who were pointing out some years ago how vast numbers of the new, mostly Hispanic arrivals were virtually the sole cause of increases in American poverty rates. It should be no surprise since we know the vast majority lack the education and skills our ever more complicated society increasingly demands, to the detriment of many natives, too, of course.

No less a poverty expert than Ron Haskins of Brookings Institution has pointed to the problems, and the astute Heather Mac Donald of the Manhattan Institute has noted how assimilation has been more and more to the underclass. A devotion to family has given way increasingly to single-parent homes with children as victims less likely to do well in school and move up, as one result.

For a variety of reasons, the flow from Mexico has decreased as the flow from Central America and Asia — a fount of needed skills — has increased. Something like a million Mexican families headed back home during the recession, and some industries that depend on unskilled labor and understandably like it to be cheap detest the Trump plan.

Here are some things to understand.

First, as a study by George Borjas of Harvard shows, legal and illegal unskilled immigrants drive down the wages of native unskilled workers by something like a whopping half trillion dollars a year. It’s also the case, he says, that immigrants get significant amounts of government assistance while paying very low taxes, meaning taxpayers must come up with about $50 billion annually to make up the difference.

It is still the case, as Borjas notes, that immigrants are a net economic gain, but that is in large part because there are educated, highly skilled immigrants who mightily boost businesses with their know-how. This nation has a deficit of sorely needed skills, as illustrated by the fact of 5.6 million unfilled jobs requiring special competence. Trump has a plan to help fix that through more vocational training, but also through his growth-spurring merit plan.

That plan calls for cutting legal entries of about a million a year to about half a million a year, and that big a drop is debatable because we need all the highly skilled workers we can get and still some unskilled, if tens of thousands fewer. At the same time, however, there are accommodation problems throughout the country, especially at our schools, and lowering the numbers will make it more reasonable on fiscal and other fronts to move toward legalization of the 11 million illegal aliens in the country now.

That’s something Trump said he would consider when the illegal flow was stopped (we’re making headway) and legal immigration was reformed.

Jay Ambrose is an op-ed columnist for Tribune News Service.