Unfortunately "could" is doing a lit of work in that sentence.

This POTUS ran on reducing grocery prices.

There's also paperwork to support the claim: certificates from suppliers of any material treated as originating, tracking systems for fungible materials, deductions for "excluded expenses," elections to group vehicles into averaging categories, confirmations of wages at some supplietd, etc.

Many seems to think it runs through April 2 when "reciprocal tariffs" are to be announced.

Yes, USMCA originating goods are not subject to the 25% duty. Non-originating goods that nevertheless are products of Mexico and Canada are subject. Non-originating potash gets a discount to 10%. There is no time limit stated in the order.

Congressional Research Service summary of IEEPA.
crsreports.congress.gov/product/pdf/...

democrats-foreignaffairs.house.gov/press-releas...

Still, this is an important step in Congress asserting its constitutional role in regulating trade and checking the President's exercise of his limited authority.

Because Congress has constitutional control over tariffs, the law also allows Congress to terminate an emergency by a resolution that is passed into law. The problem with that without a veto proof majority the President may not agree. No resolution to terminate an emergency has ever succeeded.

The President imposed these tariffs on products of Canada, Mexico, and China under the International Economic Emergency Powers Act (IEEPA). That law gives POTUS power to regulate trade to resolve an emergency.

Canada order: www.whitehouse.gov/presidential...

Mexico order, www.whitehouse.gov/presidential...

Apparently, this comes via a Truth Social post and applies to USMCA qualifying products (which is most of what is imported from Mexico). No news on Canada, but that might be just a Truth away.

There are similar documents for steel and aluminum. You best quick reference is the CBP CSMS system. Look for "Guidance" documents. www.cbp.gov/trade/automa...

The base HTSUS codes have not changed. The newly affected items are listed in the Annexes with the corresponding HS codes for the additional duties. Canada: public-inspection.federalregister.gov/2025-03664.pdf, Mexico: public-inspection.federalregister.gov/2025-03665.pdf.