Yes, the wall on our southwest border can and should be built. But it is less important than enacting the mandatory E-Verify system for employment.

Let’s face it. We all know it is the prospect of a better life through employment that attracts the vast majority of border jumpers. Our system for blocking unlawful employment of foreign-born workers who lack a lawful work permit has always been a joke, and under Obama, enforcement has been an even lower priority than it was under Bush.

Congress can turn off the jobs magnet by enacting the mandatory E-Verify program, an internet-based system allowing instant verification of the legal status of job applicants. It has an error rate of less than 1 percent and costs employers next to nothing.

Foreign born workers have no constitutional right to employment. Like every European country, Mexico and all of the advanced nations of the world, the United States has a system of “work authorization permits” for legal employment by immigrants and all foreign nationals. The problem is, our laws against unlawful employment are not enforced– in fact, they are unenforceable without major changes and improvements.

The easy availability of unlawful employment is the giant magnet motivating millions of illegal aliens to cross our borders unlawfully. We also have a mushrooming problem of millions of “visa overstays,” people who arrive on a legal tourist or other temporary visa but do not leave on the expiration date. They, too, are most often seeking employment.

If we turn off the jobs magnet, illegal entry across our borders can change from a flood to a trickle. Then the Border Patrol could concentrate on stopping terrorists and drug traffickers, and job seekers would have to get in line for one of the many LEGAL guest worker programs already on the books.

The United States already has several guest worker programs that allow employers to hire foreign workers for seasonal labor– in agriculture, in seasonal ski resorts, in landscaping, and other fields. Foreign workers are brought in for seasonal jobs where it has been demonstrated that American workers are not available — and then they go home. We even allow the hiring of year-round foreign sheep herders from Peru, Portugal and Afghanistan because, evidently, Americans will not do those jobs.

There is an important principle involved in legal guest worker programs. They are authorized only when it has been demonstrated that American workers are not available at market-based wages. Foreign workers should be SUPPLEMENTING American workers, not REPLACING them.

As a member of Congress, I sponsored a bill to allow any employer to hire a foreign worker for any job after the US Labor Department had verified that wages had been rising in that occupation for at least three successive quarters, which would be a free market demonstration of a labor shortage. If wages are flat or declining, there is no documented labor shortage.

If there are genuine labor shortages in some occupations, then by all means, let’s have a viable, LEGAL guest worker program available to employers in those fields. But that is not the case with 98 percent of the jobs now going to illegal workers. The ready availability of cheap illegal labor has been a major factor in wage stagnation over the past 20 years.

That illegal spigot must be turned off, and making the E-Verify system mandatory for all employers is the way to do it.

The E-Verify system already exists as a voluntary program administered by the U.S. Citizenship and Immigration Services (USCIS) bureau within the Department of Homeland Security. A 2014 statement by Lori Scialabba, Obama’s Acting Director of USCIS, endorsed the program as an immense success, with over a half-million employers participating nationwide: “Since it was established, E-Verify has experienced exponential growth, increased accuracy and high customer-satisfaction ratings.”

So, why hasn’t mandatory E-Verify program been adopted by Congress already? It has been included as part of some of the amnesty bills proposed over the past decade, but only as a sop to immigration enforcement, never as stand-alone legislation to fix a concrete problem.

Why not? The answer is that the E-Verify program has been opposed because the open borders lobby knows it will work. It is opposed by the US Chamber of Commerce and every other member of the coalition that supported the 2013 “Gang of Eight” amnesty bill.

Rep. Lamar Smith’s mandatory E-Verify bill, HR 1147, was approved by bipartisan committee vote in the House in 2015, but never allowed to reach the floor for an up or down vote. Sen. Grassley’s bill was considered by the Senate Judiciary Committee but similarly never allowed to get to the floor.

With Republican majorities now controlling both the House and Senate calendars, there is no valid reason not to bring these bills to a vote. Differences can be ironed out in a conference committee and a bill sent to President Trump in the first 100 days of the session.

Sadly, despite lip service paid to mandatory E-Verify by scores of Republican bill sponsors, only strong push by President Trump and his executive branch appointees can move E-Verify program to a vote in Congress. If Trump is really serious about immigration enforcement, he will make this his top priority.

The E-Verify bill will be a good test case for his White House team. Will Trump’s White House policy team prevail over the “pragmatists” who will want to wait for “congressional consensus”?

Does Trump want to fix the problem, or merely continue blaming Democrats for obstruction? In truth, on many important immigration enforcement issues, the obstruction is coming from within his own party.