Delaware has a single at-large representative in the House of Representatives. Republican incumbent Michael N. Castle was reelected for an eighth term. As of 2024, this is the last election in which a Republican was elected to Congress in Delaware.
Primary elections in Delaware are closed primaries; that is, only voters who have declared a party affiliation may vote in that party's primary.[3] Three Democrats were on the primary ballot: children's rights advocate and 2006 independent candidate Karen Hartley-Nagle, veterinarian and Vietnam War veteran Jerry Northington, and Michael Miller.[4][5] Hartley-Nagle was nominated with 55.4 percent of the vote, with turnout at 28 percent.[6] Castle did not face any Republican primary challengers.
Delaware Democratic Party House of Representatives primary, 2008[6]
In the general election, Republican incumbent Michael N. Castle was challenged by Democratic nominee Karen Hartley-Nagle and Libertarian Party candidate Mark Anthony Parks. CQ Politics forecasted the race in Delaware's At-large congressional district as 'Safe Republican'. Castle enjoyed a lead throughout the campaign, and ultimately won the election with slightly over 61 percent of the votes cast. Statewide turnout for the election was at 68 percent.[7]
Delaware's at-large congressional district election, 2008[7]