Mexico's peso slid to session lows before anyone could say what would be doubled.
President Donald Trump said he would double duties on Mexican goods unless the country stops a migrant caravan heading north.
Trump gave no deadline for Mexico to act, and his post did not say which rates or products he meant to raise.
"MEXICO MUST STOP THEM, NOW," Trump wrote on Truth Social, warning that the tariffs would be doubled if Mexico failed to act.
The group left Tapachula, near the Guatemala border, and is heading north.
The city sits about 1,150 miles from the US border, so nobody is arriving tomorrow.
Migrants walking north told reporters they saw the Democratic midterm gains as an opening for looser US immigration rules. The US Embassy in El Salvador said the results did not change US immigration law or policy.
Double what, exactly?
There is no single Mexico tariff to double.
Current rates include 25% duties on Mexican-made autos and 50% on steel and aluminum products from Mexico.
Mexican Steel and Aluminum Face Double the Tariff Rate of Autos
Current US tariff rates on Mexican goods, %, as of Nov. 12, 2026
Bar chart. Tariff Rate (%). Autos: Tariff Rate (%) 25%. Steel and aluminum: Tariff Rate (%) 50%.
Source: CBS12
A separate 10% Section 301 duty covers manufactured goods that do not comply with the North American trade pact, known as USMCA.
Goods that do comply enter duty-free. Mexico's economy ministry says more than 80% of its compliant exports to the US avoid the new tariffs entirely.
So a literal doubling could mean 20% on non-compliant goods, or 50% on autos. Those are very different bills for very different importers.
The legal runway narrowed this year
The Supreme Court struck down the entire tariff structure built on the 1977 emergency-powers law on Feb. 20, ruling it does not authorize the President to impose tariffs.
That was the statute behind the blanket 25% Mexico tariff in 2025. The ruling ended collection within days and opened the door to refunds that could reach $166B, with more than $115B already returned to importers.
What remains are slower tools. Section 301 needs a finding of unfair trade practice, and the current 10% duty rests on a forced-labor rationale. Section 232 needs a national-security finding for metals and autos, and a temporary Section 122 balance-of-payments surcharge is itself being challenged in court.
The threat also lands mid-negotiation. The US, Mexico and Canada began talks over the summer after Trump declined to extend USMCA.
Talks had momentum this fall before stalling over steel and aluminum tariffs, after Commerce Secretary Howard Lutnick pushed back on Mexican demands for lower metal duties in October.
Mexico's Foreign and Economy Ministries did not immediately respond.
The interdependence cuts both ways. Mexico is the largest supplier of goods to the US at about 17% of imports through August, and the US bought $534B of Mexican goods in 2025 against $337B it sold there.
The checkable event is a signed proclamation naming a statute, a base rate and an effective date. None of that exists yet.
