The long-running debate over what to do about undocumented immigrants currently in the U.S. — and those who may be trying to illegally enter the country now and in the future — has been taken up at least a notch or two by the Trump administration’s proposed enforcement changes.

But the emphasis — at least publicly — has been on building a new border wall.

A recent report by the Department of Homeland Security brings a less-discussed part of the equation to the fore. That’s the number of people who overstayed their visas in the U.S. in the 2016 fiscal year.

With me to talk about the significance of visa overstays is Theresa Cardinal Brown, director of Immigration Policy at the Bipartisan Policy Center in Washington, D.C.