There's some irony here in the fact that Castle, a noted RINO, was just endorsed by Chris Christie, but hey the power of the Tea Party just can't be underestimated no matter how much the Left tries to smear them:
Tea Party favorite Christine O'Donnell, a perennial candidate with no government experience, soundly defeated veteran politician Mike Castle for the Republican Senate nomination in Delaware Tuesday -- posing a major upset to the political establishment on the last big day of primaries.
With all precincts reporting, O'Donnell beat Castle 53-47 percent.
O'Donnell's win stands as the latest sign of Tea Party strength but also the latest test of whether that movement helps or hinders the Republican Party, with an open seat and perhaps a GOP Senate majority at stake.
State party leaders have warned that O'Donnell cannot compete against Democrat Chris Coons and had vigorously backed Castle, a nine-term congressman and former governor.
But O'Donnell stood her ground and accused Castle of selling out to the moderate wing of the party. Considered a long shot just weeks ago, her candidacy got renewed attention after conservative Joe Miller beat Alaska Sen. Lisa Murkowski in their state's Senatelast month. Big-name endorsements from Sarah Palin and South Carolina Sen. Jim DeMint boosted her profile in the final days of the race, which snowballed into one of the nastiest intra-party battles of the year.