At a campaign rally in Nashville on Tuesday, President Trump returned to one of his earliest campaign promises - to build a wall along the U.S./Mexico border, and have Mexico pay for it.
At Tuesday's rally, Trump joked that "I don't want to cause any problems" but said "In the end, Mexico is going to pay for the wall."
Trump has never outlined exactly how Mexico would pay for the wall, and so far has only secured funding for 100 miles of fencing
.Mexican President Enrique Pena Nieto responded to Trump on Twitter, saying "NO. Mexico will NEVER pay for a wall. Not now, not ever."
It's easy to see this statement as a "go to" that gets a big reaction at rallies - and an idea that President Trump likes to talk about but never really expects to get done.
But there actually are ways to build a wall - and, yes, have Mexico pay for it.
This article - on CNN's website of all places - has three ideas:
1. Take some of the money that immigrants send home when working in the US.
2. Seize money from drug cartels.
3. A 20% tariff on imports from Mexico.
It seems to me that President Trump's biggest challenge would involve trying to get Congress to approve an idea - so anything he could do on his own is the likeliest option.