Within recent days, prominent opponents of the Iran nuclear deal have begun quietly briefing Trump administration officials on a new argument they say makes it impossible for the president to re-certify the deal.
Why now? Trump is required to re-certify the deal every 90 days, with the next deadline coming up in mid-October. Trump also needs to decide next week whether to keep extending sanctions relief to Iran. It's very possible that Trump de-certifies Iran but still waives the sanctions — a situation that would put the onus on Congress to have the decisive word on the deal.
The new argument rests on technical disclosures
the Obama administration made to Congress under the Corker-Cardin law — the 2015 legislation that established congressional oversight over the Iran deal.