Seven years after losing to Donald Trump in the 2016 Republican presidential primary, Chris Christie is getting a rematch. Christie, the former New Jersey governor who endorsed Trump before becoming one of his fiercest critics, officially filed paperwork to run for president on Tuesday. Even before declaring his campaign, Christie has positioned himself as the candidate most willing to openly attack the former president, while other candidates tip-toe around the issue. He also is a late entry into a crowded field of Republicans, none of whom—save for perhaps Florida Gov. Ron DeSantis—have come close to challenging Trump’s popularity. But Christie isn’t deterred. “I think we’ll lose if Trump’s a nominee. That’s why I intend to be the nominee,” Christie told The Daily Beast recently. “I am the viable Trump alternative,” he said.