Maryland's 4th congressional district seat was vacant after Congressman Albert Wynn resigned on May 31, 2008. Maryland Governor Martin O'Malley announced that a special election would be held on June 17, 2008 to fill the seat for the remainder of the 110th Congress. In order to save time and money, O'Malley signed legislation to allow the Democratic and Republican parties to choose candidates by committee instead of holding primaries. As expected, both parties chose the November general election nominees (who had already been nominated in primaries for that election) as their respective June special election candidates so that either winner would be positioned to run as the party incumbent in November.
Election officials estimated the cost for holding the special election ranged from $1.05 to $1.25 million, which was borne by the taxpayers of the 4th District.