Writing in the New York Post, Paul Sperry has the scoop:

Mexico won’t have to pay for the wall, after all. US taxpayers won’t have to pick up the tab, either. The controversial barrier, rather, will cover its own cost just by closing the border to illegal immigrants who tend to go on the federal dole. That’s the finding of recent immigration studies showing the $18 billion wall President Trump plans to build along the southern border will pay for itself by curbing the importation of not only crime and drugs, but poverty. “The wall could pay for itself even if it only modestly reduced illegal crossings and drug smuggling,” Steven A. Camarota, director of research at the Center for Immigration Studies, told The Post.

As the saying goes, the right takes Trump seriously but not literally, while the left takes him literally but not seriously. No one ever expected that the president would hand Mexico a bill for the border barrier, but it was clear enough that the combined savings of fewer illegals, less crime, and fewer new dependents would add up to a significant amount of money. Throw in a tax on remittances and voila — the U.S. might even come out ahead.

Federal data shows that a wall would work. A two-story corrugated metal fence in El Paso, Texas, first erected under the Bush administration has already curtailed illegal border crossings there by more than 89 percent over the five-year period during which it was built. Absent a wall, the Homeland Security Department forecasts an additional 1.7 million illegal crossings at the US-Mexico border over the next decade. If a wall stopped just 200,000 of those future crossings, Camarota says, it would pay for itself in fiscal savings from welfare, public education, refundable tax credits and other benefits currently given to low-income, illegal immigrants from Mexico and Central America. The US Census Bureau’s latest “survey of income and program participation” shows that 62 percent of illegal-immigrant-headed households are on the federal dole — more than double the rate for households headed by native-born Americans. And that includes households where one or more workers are present in the household. Their use of US welfare is highest for food stamps and Medicaid, data show.

Not to mention the homeland-security benefit of reducing the number of terrorist infiltrators and economic migrants from elsewhere who will be discouraged or caught. Really, what are we waiting for?