He was elected to the Arkansas Senate in 2014 and took the oath of office on the first day of the 2015 legislative session.

Before his election to the Senate, he had served as an alderman in Corning.

Senator Johnson is chairman of the Senate Committee on Transportation, Technology and Legislative Affairs. He is a member of the Senate Committee on Revenue and Taxation, the Joint Committee on Public Retirement and Social Security Systems, the Joint Budget Committee and the Legislative Council.

Senator Johnson sponsored legislation setting up a pilot program under which welfare recipients undergo testing for illegal drugs, in order to qualify for benefits.

He sponsored a change in how the wealth index is calculated for school facilities funding. He was the Senate sponsor of legislation creating the Arkansas Future Grant Program.

Senator Johnson has sponsored "revolving door" legislation that requires legislators to wait at least two years after their retirement from the General Assembly before registering as a lobbyist. It also prohibits former legislators from working at an educational cooperative or local area agency on aging, until two years after they leave the legislature.

He has co-sponsored major tax relief legislation, pro-life laws and legislation that reduces the fees for concealed carry permits.

Senator Johnson is a farmer. He was born in Poplar Bluff, Missouri and graduated from Arkansas State University. He and his wife, Tricia, have a son and a daughter. They are members of the First Baptist Church of Corning.