Jim Leach was elected to the U.S. House in 1976 with 52 percent of the vote, ousting incumbent Democratic Rep. Edward Mezvinsky. He defeated Democrat Jan Zonneveld in 1992 with 69 percent of the vote. He was re-elected in 1994, defeating Democrat Glen Winekauf with 60 percent of the vote.
In 1996, he was re-elected with 53 percent of the vote against Democrat Bob Rush. In 1998, he defeated Rush with 57 percent of the vote.
In 2000, he defeated Gregory T. Guy, Davenport, Iowa, in the Republican primary for the 1st District. Leach won re-election in 2000 with 62 percent of the vote.
He was re-elected in 2002.