Marc Ambinder skeptically describes one of the pet projects of the Tea Party movement: the repeal of the 17th amendment, initially passed in 1913, which required the popular election of U.S. Senators. Before the 17th amendment, Senators were elected by state legislatures. The argument goes that repealing the 17th amendment would restore states with the power to protect their interests from federal encroachment. I don't think very highly of the Tea Party movement for the most part, but this is actually something that I have always been quite supportive of. It's hardly at the top of my "to do" list, and I don't feel particularly oppressed by a popularly elected Senate, but I do think this change would remedy not only some of the dysfunctions of the federal government, but some of the dysfunctions of state governments as well.
One of the things that I think is important to keep in mind is that this probably won't change the ideological makeup of the Senate very much. There are very liberal state legislatures out there and very conservative state legislatures. If the 17th amendment were ever actually repealed, you can be confident that voters would pay even closer attention to state-level elections, making the electorate voting in the state legislature fairly comparable to the electorate that used to vote in Senators. What it will do is produce a Senate that is more cognizant of the relationship between the federal government and the state, regardless of ideology. In 1996 it was innovative and unusual to give the states such free reign over welfare policy. Unfortunately, the same sort of federalism was not apparent in the recent health reform. A Senate composed of representatives of the state legislatures would be expected to guard the freedom of the states to differentiate themselves on issues of domestic policy on a more regular basis.
With these new found responsibilities and freedoms, hopefully we would start to see states better equip themselves to solve the problems of their citizenry. We would hopefully see less of the non-sensical disconnect between revenue and spending policy apparent in states like California. Fewer states would constrain themselves with dysfunctional balanced budget requirements if they were on the front lines of policy, rather than the faceless provincial administrators that they largely are today. Stronger federalism, such as that which would likely result from repealing the 17th amendment, means a more robust American political economy, decision making that is closer to the citizenry, and a flexibility in policy making that isn't available when the federal government dominates every decision.
Of course, while bringing more decision making closer to the people, this reform would also reduce popular control over the federal government. Is that trade-off worth it? It's hard to say for certain. I'd guess a Senate appointed by state legislatures would probably be less likely to sabotage the popular will with (excessive) filibusters and (obstructive) parliamentary procedure. In that sense, an appointed Senate may actually improve the representativeness of Senate decision making, which today is more often than not held hostage by party leaders.
It's hard to predict exactly how this would go. It's a radical change, to be sure, but I don't think it's as ill-conceived as a lot of people suggest.