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

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.”