In 1987, Martin defeated incumbent Democrat Leslie Saunders for the 67th District House of Delegates seat, 51%-49%. In 1989, Saunders challenged Martin for the seat, but Martin won 55%-45%. Due to redistricting, Martin was redrawn into the 27th District in 1991, and won the House of Delegates seat unopposed, and was re-elected in 1993. In February 1994, Martin won a special election to the state Senate in the 11th District after Robert Russell resigned after being convicted of embezzlement. He received 75% of the vote in a four-way race. Martin was easily re-elected to the seat in 1995 (he was unopposed), 1999 (won 65%-35%), 2003 (unopposed), 2007 (received 63% of the vote in a four-way race), and 2011 (unopposed).
Martin made news in 2014 when he wrote a lengthy post on Facebook claiming that pregnant women are "hosts" who have no right to end their pregnancies via abortion. "Martin said that his words were taken out of context and that he was trying to describe the way abortion advocates see women." He later edited the post to replace "host" with "bearer of the child."