Build a wall? Not so simple

Carafano said he expects to see construction of the wall soon, but the kind of barrier and the exact location will depend on many different factors and won’t necessarily result in a continuous wall along the Mexican border.

“There are parts of the desert that are so remote, you’d have to build a road to the wall,” Carafano said. “And so what you would be doing is creating a road for smugglers.”

There are lakes and other environmental obstructions to building a continuous wall, and the government will have to secure the right to build in some places that are owned privately or occupied by Native American tribes, which could take years.

The wall is already more than a decade in the making. Congress passed the Secure Fence Act of 2006 with bipartisan support. It called on Homeland Security to build a 700-mile physical barrier along the southern border.

Congress appropriated $1.2 billion to pay for the barrier, as well as additional surveillance and deterrents aimed at keeping illegal immigrants from sneaking over the border.

The wall was never really completed in the way proponents had intended with a double-layer fence. Much of the barrier consists of a fence and bollards, which are short posts used to stop vehicles and control traffic. Some places do little to stop the influx of illegal immigrants. The barrier consists in some places of barbed wire, for instance, allowing vehicle traffic to easily pass through. In other areas people can easily scale low fencing.

“The law just says build a wall,” Carafano said. “The law doesn’t say build a wall that works.”

In 2011, Obama said he believed there was no need for additional fencing because the 2006 Secure Fence Act was “now basically complete.” But the website Politifact rated his statement “mostly false.”

Trump’s plan is to build something that stops illegal immigrants from pouring over the border.

“Beginning today, the United States of America gets back control of its borders,” Trump said after signing the executive order.

Financing the project is another issue. Trump proposed on Thursday that the wall’s cost could be covered by a 20 percent tax on imports.

Republicans, who control both the House and Senate, are on board with the plan, which is really an attempt to reform the tax code in a way that taxes imports but charges companies no tax when they sell overseas. That plan would impose a border tax on all imports, but Republicans this week were playing it up specifically as a way to hit Mexico.

“We have to secure our border,” said Senate Homeland Security Committee Chairman Ron Johnson, R-Wis.

Rep. Kevin Brady, R-Texas, said Republicans have long supported the idea of a border tax.

“Our competitors are already doing this,” Brady said. “They have a major tax advantage over us in America. We believe in leveling that playing field in terms of taxation.”

Meanwhile, Carafano said real border security will require factors other than just a border wall. Carafano said the effort will require dealing with ports of entry, where illegal immigrants show up and ask for asylum, as well as the thousands of people who remain illegally in the country after overstaying their visas.

The United States must also work to stop the digging of tunnels underneath the walls, which are used to smuggle both drugs and people.

Trump’s executive order calls for adding 5,000 new Border Patrol agents and 10,000 additional customs enforcement officers to track down illegal immigrants.

Carafano said improved border security might also involve changing the laws governing how illegal immigrants are processed here so that they can be sent home quickly, rather than released into the United States.

“New authorities would be helpful in terms of how you process people and turn them back at the border,” Carafano said.