The Supreme Court heard two-and-a-half hours of arguments on the legality of Trump-era tariffs today. 

I ran the full transcript through several top AI models. And here’s how the models expect the Court to land …

OpenAI’s ChatGPT-5: Projects a 7–2 split against the government; (International Emergency Economic Powers Act) IEEPA’s “regulate importation” does not authorize revenue-raising tariffs.

Google’s Gemini 2.5: Sees a majority for the challengers, likely 6–3 or 5–4, holding IEEPA doesn’t authorize tariffs.

Anthropic’s Claude Sonnet 4.5: Expects 6–3 or 7–2 against the government; “regulate importation” doesn’t include imposing tariffs to raise revenue.

Perplexity: Anticipates 6–3 or 5–4 against broad presidential tariff authority under IEEPA.  Many Justices expressed skepticism about finding such broad power in the “regulate importation” language of the statute, without explicit Congressional authorization.

xAI’s Grok: Goes 8–1 against the administration, potentially forcing reliance on narrower authorities (like Section 232) and even phased refunds.

Bottom line from the models:  consensus view is a majority vote against Trump tariffs. 

So, would that undo the past 10 months of deal-making or unwind the global realignment achieved under Trump’s use of tariffs as negotiating leverage? 

It shouldn’t. 

Many of the deals are locked in, via bilateral agreements.  Some already fit into this “narrower” authority, where tariffs on things like steel and aluminum are legal under section 232 of the Trade Expansion Act of 1962, as threats to U.S. national security.  And broadly, the expectation is that there will be a migration to other statutes which support the tariff strategy — that just weren’t as convenient and as quick to execute as IEEPA.

With the above in mind, we get a move in Treasury yields today (higher), as markets reconsidered the deficit/revenue path — given potential refunds and a weaker outlook on tariff revenue.