Christine Therese O'Donnell is a former Republican Party candidate and conservative activist in the Tea Party movement best known for her 2010 campaign for the United States Senate seat from Delaware vacated by former Vice President Joe Biden.
O'Donnell was born in Philadelphia and began her career as a public relations and marketing consultant in the early 1990s. After attending Fairleigh Dickinson University, O'Donnell was active in Republican organizations and campaigns. She also worked for such organizations as Enough is Enough and Concerned Women for America. Later, O'Donnell established her own consulting firm.
With strong financial support from the Tea Party movement, she defeated nine-term U.S. Representative and former governor Michael Castle in Delaware's September 2010 Republican primary for the U.S. Senate, despite Castle being the favorite to take the seat back from the Democrats. In doing so, O'Donnell caused an uproar among the political establishment. She lost in the general election to Democrat Chris Coons by a margin of 57% to 40%.O'Donnell's 2010 Senate run was her third try for the office in five years. In 2008, she was the Republican nominee, losing to the incumbent , Joe Biden, by 65% to 35%. In 2006, she ran in the Republican primary for Senate, finishing third, then ran as a write-in
in the general election, drawing four percent of the vote. After 2010, O'Donnell provided commentary on the Fox News Channel and CNN.