The President's vow to impose new tariffs on Mexican imports risks sabotaging trade deals and the U.S. economy.
Leaders of 19 countries agreed to support the Paris accord on fighting climate change with the U.S. the lone holdout.
"Tariffs are B-A-D," says a deadpan Ben Stein in front of a chalkboard.
"Americans across the country" paid a stiff price last time.
The president, who announced the protectionist measures on Thursday, later tweeted that "trade wars are good, and easy to win."
America's prosperity depends on turning outward to the rest of the world.