(CNN) - Add another Republican to the race for Vice President Joe Biden's old Senate seat.
Christine O'Donnell formally announced her candidacy Wednesday. O'Donnell, a conservative commentator and marketing consultant who ran unsuccessfully for the Senate in 2006 and 2008, had been talking about running again since last summer. She will now face off for her party's nomination against Rep. Mike Castle, Delaware's 9-term at-large congressman and a former 2-term governor of the state,
"Delaware voters deserve a candidate who understands that governments can't spend their way to recovery and they cannot tax the country into prosperity. That is why I have made the decision to run for US Senate," said O'Donnell at a kick-off event at the University of Delaware's Wilmington campus. "The problem is we don't have enough elected leaders who understand that, far too often, the actions of Congress kill job growth and lead to higher taxes and bigger deficits."
Castle's campaign tells CNN that "Mike welcomes all candidates who enter the race for United States Senate and looks forward to this campaign. He is committed to keeping both Congress, and this campaign, focused on solutions to issues that voters care about– economic growth, runaway federal spending, and getting Delawareans back to work."
The winner of November's general election will fill out the remaining 4 years of Biden's final term. Biden stepped down from the Senate after his election in November 2008 as vice president. Former Biden aide Ted Kaufman was named as an interim replacement. Kaufman is not seeking a full term. After much speculation that he would run for his father's old seat, Delaware Attorney General Beau Biden announced in late January that he would instead run for re-election as his state's top lawyer. Nine days after the younger Biden's announcement, New Castle County Executive Chris Coons officially announced his candidacy for the Democratic nomination.
Political handicappers consider the Delaware seat a prime pick-up possibility for the GOP and national Republicans agree.
"While the NRSC is neutral in the Republican primary, we consider this a unique and very viable opportunity to pick-up the Vice President's former Senate seat this November," Amber Marchand, National Republican Senatorial Committee spokeswoman, told CNN.
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