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Trump supporters are convinced that Joe Biden's coughing fits during campaign stops in Detroit means he will call out sick before debates.

On Wednesday, Sept. 9, Biden visited Detroit, Michigan -- one of the swing states he needs to defeat Trump in November.

While Trump holds massive rallies around the country, Biden prefers small intimate gatherings of five or six supporters and friendly journalists in attendance.

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Biden spoke with members of the United Steelworkers union in a supporter's back yard on Wednesday. The 77-year-old Democratic presidential nominee began experiencing coughing fits.

Biden also coughed a dozen times while speaking at another campaign stop in Michigan.

He pulled down his black face mask down and touched his nose -- against the CDC's advice not to touch the face to avoid contracting the virus from contaminated hands.

Trump supporters believe Biden's coughing fits are proof that his team will say he is too sick to debate with Trump. The first debate is scheduled for the end of this month.