Magoffin became active in the Democratic Party, serving as a presidential elector in 1844, 1848, 1852, and 1856 and as a delegate to the Democratic National Convention in 1848, 1856, 1860, and 1872. He served one term in the Kentucky Senate in 1850, but declined his party's nomination for a seat in the U.S. House of Representatives in 1851. In 1855 was the Democratic nominee for lieutenant governor, running on a ticket with Beverly L. Clarke, who was defeated by Know Nothing candidate Charles S. Morehead.