 Prior to 2007, he had last been challenged in 2001 by Dale Evans, a real estate agent, and won with 60.05% of the vote.As the only Republican state legislator within the Capital Beltway, Callahan was considered a target by Democrats keen to secure their hold on Northern Virginia.On March 6, 2007, Callahan announced that he would not run for re-election in November 2007.