From Maine lobsters to Michigan autos, trade with Canada matters in states that could determine control of the U.S. Senate.

CHICAGO (AP) — President Donald Trump's barrage of tariffs — and threats of even more — has strained the United States' longstanding relationship with Canada.

President Donald Trump threatened to double tariffs on Canadian cars on Monday, the latest sign that the United States and Canada are barreling toward a deeper trade war after…

The tariff criticism from Democrats is part of a larger strategy focused on tapping into voter anxieties about the economy.