The National Association of Letter Carriers, the union representing roughly 300,000 current and former postal workers, on Friday endorsed Joe Biden in the 2020 presidential election, calling him "a fierce ally and defender of the U.S. Postal Service," reports NBC News.

Why it matters: The endorsement comes as President Trump has vowed to block additional funding for the USPS in the next coronavirus stimulus package, linking it to his continued baseless claims that increased mail-in voting will lead to widespread voter fraud.

What they're saying: "This pandemic threatens the very survival of USPS. Yet, while postal employees are on the front lines providing essential services to the public every day, the current administration refuses to provide the necessary financial relief that would strengthen the agency during this pandemic," the union's president, Fredric Rolando, said in a statement.

Worth noting: Fraud from mail-in voting has historically been rare, according to the Brennan Center, with Oregon — a state that votes primarily by mail — documenting only about a dozen cases of fraud out of more than 100 million ballots since 2000.