Is Trump already a lame duck — or more dangerous to Canada than ever?

WASHINGTON, D.C. — ​​As Canada reels from another round of tariff threats and White House ultimatums, many in Ottawa and the business community are watching Washington for a different reason: U.S. President Donald Trump says he won’t run again in 2028, raising the question of whether his final years in office will finally bring relief — or more turmoil — north of the border.

Some scholars in Washington fear he will challenge the 22nd Amendment, which limits presidents to two terms. Others...