Supplement Rather than Repeal the Seventeenth Amendment
There is growing consensus that the federal structure of the U.S. Constitution was greatly undermined by the Seventeenth Amendment, adopted in 1913. Of course, that Amendment moved the selection of U.S. Senators from the state legislatures to direct popular voting in each state. But those who favor repealing the Seventeenth Amendment overlook some of the real problems that it addressed, such as frequent deadlocks in the state legislatures, plus the strong and reasonable desire for more oversight by the general public. In my view, we could get the best of the pre-1913 and post-1913 worlds with a new Amendment that supplements rather than repeals the Seventeenth:
Each state may enact that any general election by its people of a United States Senator shall involve only two different candidates, each nominated by a respective house of its legislature, or by its unicameral legislature. Without such a state law or timely nominations accepted thereunder, this amendment shall not apply.
This would solve the pre-1913 problems of legislative deadlocks and ineffective public oversight. And it would also recover the pre-1913 benefits such as giving states a stronger check on the national government's consolidating tendencies, bringing personal acquaintance and accountability to the selection process, making life more difficult for lobbyists and other special interests in Washington D.C. because legislation would have to be approved by a House and Senate that are more distinct and different from each other, and avoiding expensive U.S. Senate primaries that draw relatively few eligible voters.
Madison once posed this question: "Will it be sufficient to mark, with precision, the boundaries of these departments, in the constitution of the government, and to trust to these parchment barriers against the encroaching spirit of power?" The answer is a resounding "no," and I hope we improve the checks and balances that are necessary to preserve the boundaries that the Constitution purports to establish.