Sam Johnson was elected to the Texas House in 1984 and served seven consecutive terms.
Johnson defeated Republican Tom Paukin in a 1991 special election to replace Rep. Steve Bartlett who resigned his U.S. House seat to run for mayor of Dallas. Johnson won 53 percent of the vote.
He was elected to full terms in 1992 and 1994 with no major party opposition. He was re-elected in 1996 with 73 percent of the vote against Democrat Lee Cole. Johnson was re-elected in 1998 without major party opposition. He was re-elected in 2000 with 72 percent of the vote.
In 2002 he won re-election with 74 percent of the vote. In 2004, he beat a primary challenger with 84 percent of the vote and has no opposition in the general election.