Delaware Democrat Chris Coons beat out Republican Christine O'Donnell for the open Senate seat once held by Vice President Joe Biden.
The Tea Party-backed candidate O'donnell surprised the Republican establishment when she ousted their pick Rep. Mike Castle to won the party nomination in the primary.
Castle, a popular former governor, had been heavily favored to win Vice President Joe Biden's old seat.
Coons is a wealthy attorney and the stepson of the founder of the company that developed Gore-Tex fabrics. He is the executive of the state's largest county and mostly supports the Obama administration's agenda.