California set this precedent roughly a decade ago [0] with no challenge. It will stand.

Subnational diplomacy is the norm in most federations, hence why GOP led Iowa [1] and Montana [2] lobbied in favor of India with Trump leading to the current trade deal [3].

[0] - https://calmatters.org/environment/2017/11/gov-jerry-brown-t...

[1] - https://governor.iowa.gov/press-release/2025-09-07/gov-reyno...

[2] - https://www.daines.senate.gov/2026/01/20/daines-travels-to-i...

[3] - https://www.reuters.com/world/india/us-trade-chief-says-indi...