The 17th Amendment as a Design Problem

I've been mostly indifferent to recent back-and-forth regarding the utility/propriety of the 17th Amendment; neither method of election, direct or indirect, seems obviously superior to me. Todd Zywicki, however, makes an interesting argument in favor of repeal that I've never considered before:

The bottom line question is what system of selection of political officers will best further the goals of the Constitution. I happen to think that the original framework was a pretty good balance of creating a republican government that would tame agency costs by political actors, preserve individual liberty, and frustrate special interest rent-seeking. Non-democratic appointment of judges with shared authority between the President and the Senate, direct election of House members, state election of Senators, and the elaborate state-based architecture of the Electoral College* strikes me as an ingenious and well-balanced system.

There's certainly merit in that position. I think there's also an argument from fairness to be made here: Under the current system state governments don't have a direct voice at the Federal level. If state governments are legitimate stakeholders in the running of the country then giving them such a voice via the Senate, while preserving the People's control of the House, is more fair that providing the People with two vehicles for representing their views while shutting out the states.