Florida congressman Ron DeSantis announced his candidacy today for the Senate seat vacated by Marco Rubio. He’s the first Republican to announce, and he’s been endorsed by a bevy of tea-party groups as well as by the Club for Growth.

DeSantis, who is 36, was elected in 2012 and is pretty solidly a member of the House’s tea-party bloc. In his announcement today, he called himself part of a “new generation” of conservatives and made it clear he sees himself as both a credible and worthy successor to Rubio. Whether he gets a strong primary opponent will depend, it seems, on whether the Republican establishment can field a self-funder to challenge him.

On the Democratic side, the party has lined up behind representative Patrick Murphy, but their plans could be upended if another Florida congressman — Alan Grayson — decides to jump in, too. That would set up a bloody primary on the Democratic side between the center-left Murphy and the left-wing Grayson.