The main candidates in the U.S presidential primaries, Democrat Joe Biden and Republican Donald Trump, have comfortably won in Michigan. But their respective triumphs have also entailed a cost, and reveal the problems they suffer among part of their electorate.

The main key: the “undeclared” vote to protest against Biden. Trump also exhibits weaknesses for the former president and Republican candidate to return to the White House, this Tuesday's election event offered the opportunity to make clear the support he has.