Donald Trump

President Donald Trump in the Oval Office of the White House in Washington, Monday, June 26, 2017. (AP Photo/Evan Vucci)

Evan Vucci

With an eye toward one of his winning issues in the last campaign, President Donald Trump is now seeking to reopen the national debate over immigration.

The proposal to restrict and reshape legal immigration is based on some shaky assumptions, such as the idea that low-wage green-card holders are flooding in to take jobs from Americans.

We question whether that is the economic reality. A campaign can get away with broad statements that depart from the facts. A functioning government must be reality-based.

Particularly for port cities like New Orleans, immigration has always been part of the growth formula that has increased wealth for the nation, for many decades.

In New Orleans, Baton Rouge and Lafayette, which host major universities, international students have helped communities grow. Many students from abroad marry and resettle in Louisiana or elsewhere in this country, enriching our society.

It may sound fine to allow only "meritorious" immigrants like college graduates, but the process of exclusion cannot neatly be performed on a national scale. Who gets in? Who decides? Further, Louisiana is heavily dependent on agriculture and fisheries on seasonal and typically migrant labor.

We don't doubt that there have been abuses in any nationwide government activity like immigration management, but the fact is that immigration is good for the nation, and particularly for Louisiana.

Most economists say the benefits of immigration outweigh the costs — a point made in a letter to congressional leaders in April that was signed by 1,470 economists, six of them Nobel laureates.

Researchers have also found that in many states, the benefits of consumer spending by immigrants and taxes paid outweigh any government costs. Louisiana is, after all, the state with the highest average sales taxes in the nation; by and large, the state makes money on milking the pocketbooks of lower-wage earners, at a far higher percentage than the wealthier among us.

Recent statistics show that the Baton Rouge metropolitan area actually lost about 2,000 people during the first years of this decade, but that loss was more than offset by international migration, according to The Brookings Institution think-tank.

William H. Frey of Brookings is perhaps America's leading demographer. He should be consulted by the president: "It has often been the case that immigrant flows are 'bimodal' with respect to their educational attainment," Frey recently wrote. "That is, compared to the resident population, new immigrants are more likely to be overrepresented at both the upper tiers and lower tiers of educational attainment."

The president ran into a bit of trouble when he found out that health care policy was a more complex problem than he originally thought. He might find the same with immigration. We don't want to dismiss any constructive discussion, but basing policy on facts instead of suppositions is critical to the immigration debate.