[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/09/12/art.odonnell.castle.2shot.candidates.jpg caption ="Rep. Mike Castle finds himself in a tight primary race with Tea Party favorite Christine O'Donnell in Delaware's GOP U.S. Senate primary on Tuesday."]
(CNN) - Nine-term Republican Congressman Mike Castle finds himself in a tight primary race with TV commentator and Tea Party favorite Christine O'Donnell in Delaware's Republican U.S. Senate primary on Tuesday.
In the closing days of the primary campaign, O'Donnell has gotten a boost with an endorsement by former Alaska Gov. Sarah Palin and more than $150,000 in late spending from the Tea Party Express. All this has the Republican establishment worried that O'Donnell could take down the Republican they believe is best positioned to win in November.
O'Donnell has positioned herself as a conservative gate-crasher.
"We're breaking up the backroom deals," she told CNN. "We're restoring the political process back to the hands of the people." She refers to Castle as the "anointed one."