I’m blowing out my voice to get this sucker done,” Trump told the crowd after his mic stopped working mid-rally.

DETROIT—Donald Trump does not apologize. Ever. It’s actually a point of great pride for him. But his return to Michigan on Friday showed that, at least briefly, he understood he had stepped in it last week in a city that could dictate the fate of this state’s 15 electoral votes.

The greeting came after a 17-minute audio failure that left the former president unable to communicate with the audience that gathered to hear him speak Friday night in Detroit, at a rally in one of the nation’s largest swing states.