Etheridge was elected to the Tennessee Senate in 1869, representing the 22nd district (Weakley, Obion and Henry counties). He spent much of his term calling for the repudiation of the state's debt, which was getting out of control (the state debt would be the dominant issue in state politics over the subsequent decade). He also supported a call for a constitutional convention. This convention, which took place in 1870, restored the right to vote to former Confederates, and as a result, Democrats regained control of the state government.