President Joe Biden has voiced support for Amazon workers in Alabama who are voting on whether to form a union. Biden posted this message to Twitter on Sunday evening.

President Joe Biden: “Unions lift up workers, both union and nonunion, and especially Black and Brown workers. I made it clear, made it clear when I was running, that my administration’s policy would be to support unions organizing and the right to collectively bargain.”

Some 6,000 Amazon workers in Alabama have until the end of the month to cast ballots in what could become the first successful union drive at a U.S. Amazon warehouse.