“This whole thing looks like a real stretch to me, and is probably going to collapse soon as questions about it escalate,” said James C. Capretta, a resident fellow at the American Enterprise Institute, and a top budget official during the George W. Bush administration.

The drug card promise was presented as a centerpiece of Mr. Trump’s health care agenda, what he called “another historic provision to benefit our great seniors.” Such boasts are becoming routine. Since the 2016 campaign, the president has repeatedly promised that a comprehensive overhaul of the health care system was imminent, that some measure was coming to protect people with pre-existing medical conditions, regardless of his push to repeal the Affordable Care Act and its protections, and that prescription drug prices were coming down substantially…

Many of the officials assigned to enact the policy view it as legally dubious. Generally, major changes in Medicare policy require Congress to pass legislation. And numerous officials balked at the election-eve timing of the plan, fearing liability if they delivered what the White House wanted. Mr. Meadows acknowledged that pushback on Wednesday.

“I think that was a concern that there might have been a look that this was done for a political motivation,” he said. “That’s not the case.”