The United Auto Workers union announced Tuesday that it is endorsing former Vice President Joe Biden in this year's election.

Why it matters: The union is influential in Michigan, a key swing state and hub of the auto industry that President Trump won in 2016. The union represents about 400,000 auto workers and 580,000 retired workers around the country.

Between the lines: The union endorsed Hillary Clinton in 2016, but 33% of its members voted for Donald Trump in that election, drawn to his message on trade. The state voted for Barack Obama in the previous two presidential elections.

What he's saying: “In these dangerous and difficult times, the country needs a president who will demonstrate clear, stable leadership, less partisan acrimony and more balance to the rights and protections of working Americans,” said Rory Gamble, president of the UAW.

“UAW Members need a federal government that ensures that members have both a good job to go to, and that they come home to their families at night having earned a fair day’s wage in a safe and secure place.”

Go deeper ... Buckle up: GM, Michigan and 2020