Jon Holmes loves to keep up to date with the latest news.
Donald Trump has insisted the wall between Mexico and America will still happen, and that Mexico will find a way to pay for it.
But Jon Holmes thought he had better find out how a wall like that would be created, so he invited Ground Force's Tommy Walsh to explain.
Walsh predicted it would measure just under 2,000 miles, and would have to have holes in it, so the wind didn't knock it over. Though he did suggest decking and water features to make it look nicer.
He reckoned it would also cost at least £1 million a mile, and need to be at least 25 foot high, so Donald Trump probably wouldn't even be alive by the time it was finished.
Listen to the full interview to find out more