“The people in Michigan, they want jobs and paychecks,” said Schuette, a 63-year-old former congressman, state senator and appellate judge from Midland.

Mr. Obama was a state senator from Illinois in October 2002 when he famously condemned Iraq as a “dumb war.”

State senator Bill Cunningham supported the measure in part because his wife is a former hairstylist whose customers frequently discussed incidents of domestic violence.