In 1974 Dyson was successful in seeking one of the three delegate seats shared by Charles and St. Mary’s Counties and led the ticket in the Democratic Primary, forever earning the animosity of then-Speaker of the House John Hanson Briscoe for piling up more votes than the Speaker in his home county.
Dyson went on to run and win the Democratic nomination for Congress just two years later and ran an unsuccessful campaign against incumbent Republican First District Congressman Bob Bauman. Bauman, a rising star in the GOP for his mastery of the rules of the House of Representatives was a thorn in the side of Speaker Tip O’Neill and Dyson’s campaign was able to attract national money to his effort, but the district was fully in Bauman’s camp