Admonishing his own party, President Barack Obama says it would be “inexcusable” and “irresponsible” for unenthusiastic Democratic voters to sit out the midterm elections, warning that the consequences could be a squandered agenda for years.

“People need to shake off this lethargy. People need to buck up,” Mr. Obama told Rolling Stone in an interview to be published Friday. The president told Democrats that making change happen is hard and “if people now want to take their ball and go home, that tells me folks weren’t serious in the first place.”…

“It is inexcusable for any Democrat or progressive right now to stand on the sidelines in this midterm election,” Mr. Obama said.