As of 2008, Democrats had controlled the Delaware governorship for 16 years. In an upset, state Treasurer Jack Markell defeated Lieutenant Governor John Carney by 51 to 49% for the Democratic nomination on September 9. The Republican nominee was former state Superior Court Judge William Swain "Bill" Lee, defeating airline pilot Michael Protrack. Lee was the Republican nominee for Governor in 2004, and lost to Minner by a narrow margin.
The race got more attention due to the Vice Presidential candidacy of U.S. Senator Joe Biden. Since Biden, a senator, was elected to be Vice President, he needed to resign his Senate seat. The new Governor was then called upon to appoint someone to replace Biden in the Senate. Since Lee would naturally have been more inclined to select a Republican, his election could have caused a Republican pickup in the Senate by proxy. However, he was defeated by a wide margin on election day by Markell. Senator Biden resigned his seat in the United States Senate on January 15, 2009, and Governor Minner appointed Ted Kaufman to Biden's seat. Kaufman had previously served as Senator Biden's Chief of Staff during his tenure in the United States Senate.