Tea party-backed O'Donnell wins upset in Del.

Republican Senate candidate Christine O'Donnell addresses supporters after winning the Republican nomination for Senate in Delaware, Tuesday, Sept. 14, 2010, in Dover, Del. O'Donnell upset Rep. Mike Castle.. (AP Photo/Rob Carr)

September 16, 2010 8:29:00 AM PDT

By RANDALL CHASE

WILMINGTON, Del. (AP) - September 14, 2010 --

Conservative activist Christine O'Donnell earned a stunning victory in Delaware's Republican Senate primary Tuesday, riding a wave of tea party anger and advertising dollars to defeat U.S. Rep. Michael Castle.