ABC News’ Devin Dwyer reports: Christine O’Donnell, the Sarah Palin and Tea Party backed candidate, dealt a stunning blow to the Republican establishment Tuesday night, defeating the moderate, party-favorite veteran Rep. Mike Castle in the Delaware GOP senate primary.
With 99 percent of precincts reporting as of 9:21 pm, O’Donnell had 53.2 percent of the vote to Castle’s 46.8 percent. AP projected O’Donnell the winner.
Castle’s impending loss immediately casts doubt on GOP chances of winning the senate seat, which had been held by Democrat Joe Biden for 36 years, and could close the door on a Republican effort to gain control of the Senate in November.
Unlike Alaska, where conservative lawyer Joe Miller shocked Republicans by defeating sitting Sen. Lisa Murkowski in last month's primary, Delaware is a heavily Democratic state and recent polls have shown O’Donnell would face a much more difficult race against Democrat Chris Coons than would Castle.
The question now is whether the Republican establishment, which has spent weeks trashing O’Donnell, will go to bat for her in the race against Coons and whether the intraparty attacks will hurt her candidacy in the general election.