In 1974, Isakson first ran for the Georgia House of Representatives in an eastern Cobb County district and lost. He ran again in 1976 and won. He served seven terms in the House. He won re-election unopposed in 1984 and 1988. In his last four terms (1983–1990), he was the Republican Minority leader. In 1988 and 1996, he was co-chair for U.S. Senator Bob Dole's presidential primary campaigns.
