Kind of a misleading headline there. Navarro upheld a ruling that Castro didn't have standing to bring the suit.

Apparently, Castro sued to have Trump removed from the ballot, but the court said "Who the fuck are you? You're no one. You don't have standing." So Castro filed the paperwork for a Presidential run specifically so he would have standing for the suit, but Navarro wasn't buying it - you can't manufacture the conditions for your own standing.