Trump (again) threatens to seal U.S.-Mexico border. Can he do it?

Alan Gomez | USA TODAY

Show Caption Hide Caption Donald Trump threatens to close southern border with Mexico President Donald Trump on Friday threatened to close the nation's Mexican border or large sections of it next week, a potentially drastic step affecting both nations' economies, if Mexico does not halt illegal immigration at once. (March 29)

In a series of tweets fired off Friday morning, President Donald Trump revived a long-standing threat to seal off the southern border if Mexico doesn't do more to stop U.S.-bound migrants crossing through that country.

"If Mexico doesn’t immediately stop ALL illegal immigration coming into the United States throug our Southern Border, I will be CLOSING…the Border, or large sections of the Border, next week," he tweeted.

Trump's threat revived the same questions posed when Trump first made his threat in October: Can he do it? And should he do it?

The first question, whether Trump can close the border, is a simple one to answer: yes.

"You can certainly stop entries coming across the border, whether it's truck traffic or cars or pedestrians," said Gil Kerlikowske, former commissioner of U.S. Customs and Border Protection. "Logistically, that's possible. The gates are closed, and you say, 'Right now we're not taking entry.'"

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Other presidents have done that in extreme situations.

President George W. Bush partially closed the southern border following the 9-11 terrorist attacks, requiring full inspections of every incoming pedestrian and vehicle that led to days-long waits. President Ronald Reagan temporarily closed ports of entry along the southern border in 1985 following the kidnapping and murder of a DEA agent in Mexico.

But those closures were not nearly as controversial, leaving a Trump border closure open to potential lawsuits. The Trump administration has already been shot down by federal judges over multiple attempts to limit migrants trying to cross the southern border, including an attempt to cut off asylum for migrants who enter the country illegally.

The broader question of whether Trump should close the border is even more difficult to answer.

....In addition to stopping all payments to these countries, which seem to have almost no control over their population, I must, in the strongest of terms, ask Mexico to stop this onslaught - and if unable to do so I will call up the U.S. Military and CLOSE OUR SOUTHERN BORDER!.. — Donald J. Trump (@realDonaldTrump) October 18, 2018

Peter Boogaard, a former Homeland Security official in the Obama administration now working for fwd.us, an immigration advocacy group, said closing down border crossings with America's third-largest trading partner would be a crippling blow to the economy. He said the damage would be felt throughout the country, not just the four border states.

"We're talking about more than a billion dollars a day, including a huge percentage of the food that is in grocery stores," Boogaard said. "We’re literally talking about an inability to stock grocery stores because of the amount of produce that comes from Mexico."

The U.S. State Department estimates that $1.7 billion in goods and services, and hundreds of thousands of people, legally cross the border each day. The U.S. gets nearly half (44 percent) of its fresh fruits and vegetables from Mexico, according to the U.S. Department of Agriculture.

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Even groups that generally approve of Trump's efforts to limit legal and illegal immigration have expressed reservations over his threats to seal the border.

"There's a reason ports of entry exist," Mark Krikorian, executive director of the Center for Immigration Studies, said in October after Trump first started making the threats.

That’s why Krikorian said Trump cannot seriously be considering a full closure of the border. Krikorian believed Trump is either bluffing to get Mexico to stop the caravan for him, or simply using the threat to rile up the Republican base.

"This really does exemplify how Trump articulates what a lot of ordinary people feel when they see," a caravan of migrants headed toward the U.S., he said. "That's part of his strength — he gives voices to the reaction that normal people have to news events."

It's also unclear how closing ports of entry would stop migrants seeking to request asylum in the U.S. The Trump administration has limited the number of migrants who can request asylum each day at the ports of entry along the southern border. But U.S. law allows migrants to enter the country illegally and then request asylum.

That's what tens of thousands of Central Americans have been doing in recent months. They've been crossing the border between ports of entry, seeking out a Border Patrol agent, and requesting asylum that way.

"Sealing the border does absolutely nothing to impact this," Boogaard said.

Trump's threat was part of an administration-wide offensive to portray the situation along the southern border as a "crisis" that has reached the "breaking point," with the heads of the Department of Homeland Security and Customs and Border Protection claiming the flood of asylum-seeking migrants from Central America has overwhelmed the U.S. capacity to process them.

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