This is all about migrants and drugs like their election was about eggs, Trump voters were just "economically anxious," and non-voters cared so much about genocide in Palestine. Nonsense.

That said, there's good historical info in this link I didn't know about, like:

Trump used the International Emergency Economic Powers Act of 1977 (IEEPA) to apply the tariffs, marking the first time the law had been used to apply levies to countries.

and

Trump threatened to apply broad tariffs to Mexico in 2019 over immigration issues, invoking IEEPA, but ultimately did not use them. Richard Nixon used a precursor to IEEPA, the Trading With the Enemy Act of 1917, to briefly apply tariffs of 10 per cent on US trading partners.

For anyone scrolling, read a more Canadian perspective about the impact of this trade war here.