The endorsement of the 400,000-member union is critical for Mr. Biden as he seeks to bolster his support among working class Americans.

He became the first president in modern history to join a picket line when he visited striking workers near Detroit in September. In his announcement during the UAW’s political convention in Washington, D.C., UAW President Shawn Fain said the union hopes the person who’s going to sit in the most powerful seat in the world will help the UAW win as a united working class.

Fain closed by saying the UAW is endorsing Joe Biden in his re-election bid to be the United States President for a second term.