FORT MITCHELL, Ky. — Hillary Clinton already has an assignment for her husband, Bill Clinton, if they return to the White House next year. The former president, Mrs. Clinton told voters on Sunday, will be “in charge of revitalizing the economy.”

“Because, you know, he knows how to do it,” she said. “Especially in places like coal country and inner-cities and other parts of our country that have really been left out.”

Mrs. Clinton mentioned her idea for her husband while speaking at a rally outside a home in northern Kentucky. Earlier this month, she said she had told Mr. Clinton that he would need to “come out of retirement” to help put people back to work.

Mrs. Clinton spent Sunday campaigning in Kentucky ahead of its Democratic primary on Tuesday. At the rally here, she cited the economic success of her husband’s presidency while outlining her own plans. She also emphasized her commitment to supporting workers in the coal industry, which has a major presence in Kentucky, just as it does in West Virginia, where Mrs. Clinton lost the primary last week to Senator Bernie Sanders of Vermont.