More: The idea emerged, the sources said, as Olsen and other officials brainstormed about how the federal government could take control over elections from U.S. states, an idea publicly aired by Trump.

Olsen wanted a national system of hand-counted paper ballots, the sources said, a frequent Trump demand some election-security experts say would be less accurate and potentially riskier than the current system of machines with auditable paper trails that almost all cities and states use.