President Donald Trump blindsided many of his own administration officials and allies with his vow to pay all American adults $5,000 if Republicans keep control of Congress, prompting an internal scramble on Thursday to backfill the proposal’s specifics, two people familiar with the matter told CNN.

Trump made the pledge during his speech at the GOP’s midterm convention after discussing it with only a small circle of close political advisers, including Jason Miller and James Blair, a Trump political adviser told CNN. That left most officials across the administration unprepared to manage the fallout of a $1 trillion proposal that has already faced widespread blowback over its price tag and feasibility.

Several Republican lawmakers immediately panned the idea as a misguided ploy ahead of November’s midterm elections that would be nearly impossible to pass through Congress — not to mention one that would violate many of the party’s core economic principles. Even on the convention floor, some attendees were skeptical.

“I’m not into free stuff,” Arlington small business owner Wilma May told CNN in Dallas. “I would prefer him to give $5,000 towards paying down the deficit.”

The vow also alarmed GOP economists and some close Trump allies, some of whom dismissed it as a poor attempt to effectively bribe voters to keep Republicans in power.