Former Texas Representative Robert O’Rourke formally announced earlier Thursday morning that he’ll seek the 2020 Democratic presidential nomination, ending months of anticipation over whether he’d try to translate his newfound political celebrity into a White House bid.

Until he challenged Republican Sen. Ted Cruz last year, O’Rourke was little known outside his hometown of El Paso. When he ran for the Senate against Ted Cruz, however, his campaign received the most amount of campaign contributions in US Senate history, and he only lost the race by 3 percentage points.

“This is going to be a positive campaign that seeks to bring out the very best from every single one of us, that seeks to unite a very divided country,” O’Rourke said in a video announcement with his wife on a couch. “We saw the power of this in Texas.”

Beto O’Rourke is to join a presidential primary full of candidates from all over the left political spectrum, and his charisma and grassroot support from Texas is to be tested.