While civil servants have stepped up to fill gaps, their power and influence is limited — and many senior career government workers have quit or retired since Trump took office, taking institutional knowledge with them.

Max Stier, who tracks federal vacancies as head of the nonprofit Partnership for Public Service, likened the administration to a government run by substitute teachers.

“You imight have a wonderful educator coming into the class for a day, or a week, or a couple of weeks,” he said. “But they get no respect.”

For millions of Americans, the consequences are real. Vacancies have stalled pay raises for thousands of federal workers. A mortgage rule to help home buyers has been stuck in limbo for more than a year. And the Internal Revenue Service is short bodies to push out regulations related to the new tax law, stymieing businesses.