Trump's new threat of tariffs on Canada and Mexico will hit far beyond autos and retail, with chemicals companies and freight rails key cross-border players.

Trump tested the waters on tariffs during his first four years in office. Almost immediately, “Trump hit a slew of countries with tariffs on steel and aluminum,” according to the New York Times, then “wielded those taxes as leverage against Canada and Mexico to renegotiate NAFTA.”

Trump plans 25% tariffs on Canada, Mexico. What will it mean for Iowa's economy, farmers? Last time it left a $2 billion dent