The seat was vacated by Mike Castle, who announced his retirement from the House to pursue his unsuccessful run for Vice President Joe Biden's former Senate seat.

Mike Castle and I are great friends.

Republican incumbent Mike Castle decided to run for the U.S. Senate instead.

She inflicted a shock defeat on Mike Castle, the mainstream Republican candidate, who had served nine terms in the US House of Representatives after being governor of the state.

O'Donnell is now 11 points behind in the polls in that state, whereas Mike Castle, the moderate Republican she beat last Tuesday, had been strongly ahead.

At Large District'Incumbent: Mike Castle(R)

To put it into context, Mike Castle has been Delaware's congressman since 1992, that's 18 years.

It's includes moderates such as Mike Castle of Delaware, and more conservative House members like Pete Sessions of Texas and Tom Feeney of Florida.

"I've never seen Rick too much in a funk," says Mike Castle, a Delaware congressman who was elected to the House with Lazio in 1992.

An example of these situations is Mike Castle, then Representative for Delaware who ran in 2010 for Senate seat vacated by Vice President Joe Biden.