President Trump took to Twitter early Sunday to declare that the race for Democratic National Committee chairman was “rigged,” saying that Keith Ellison, a candidate backed by Bernie Sanders, never stood a chance.

Tom Perez, a labor secretary under Barack Obama, narrowly won the race over Ellison, a congressman from Minnesota who was endorsed early by Sanders, the senator from Vermont who was the runner-up last year for the Democratic presidential nomination.

“The race for DNC Chairman was, of course, totally ‘rigged,’” Trump tweeted shortly after 6:30 a.m. “Bernie's guy, like Bernie himself, never had a chance.”

“Clinton demanded Perez!” Trump added, referring to last year’s Democratic presidential nominee, Hillary Clinton.

Trump cited no evidence to back up his claim.

Clinton didn’t offer a formal endorsement in the DNC race, although she and Perez have long been political allies and Perez was widely considered the candidate of the establishment wing of the party. Perez backed Clinton over Sanders for the Democratic nomination last year.

Trump has claimed for months that the Democratic race for president was “rigged” in favor of Clinton and against Sanders. He also frequently used the same term to describe his race against Clinton.

Since the election, Trump has claimed, without evidence, that there was widespread illegal voting on behalf of Clinton that cost him the popular vote. Although Trump prevailed in the electoral college, nearly 3 million more people voted for Clinton.