Former president has given series of blistering speeches to help candidates in key races – and deployment has proved a hit with party’s progressive wing

That could have been awkward. Barack Obama , campaigning for Senate candidate Abdul El-Sayed in Michigan, acknowledged that his fellow Democrat has criticised some aspects of the Obama presidency.

“Yeah, Abdul didn’t agree with some things we wanted to do – that our administration was doing – when I was president,” he told a rally in Detroit . “You know who else doesn’t agree with everything I do? Michelle Obama.” The crowd erupted in laughter. “I’d say about five times a day, she says, ‘You knucklehead. Why you do that?’”