In what may be a first at the U.S. Supreme Court, President Donald Trump's Twitter account was identified Monday as an “authority” along with the cases, law review articles and news citations that lawyers typically use to bolster their arguments.

The cited authority—”Donald J. Trump (@realDonaldTrump), Twitter (June 5, 2017), https://twitter.com/realdonaldtrump—came from the challengers to the president's second executive order restricting travel from certain Muslim-majority countries.

Those challengers, represented by Hogan Lovells partner Neal Katyal, in the case Trump v. Hawaii, are urging the high court to reject a Trump administration request that would void a trial judge's order blocking the travel ban from taking effect.