From the American Thinker, here:
Dear Sean:
Concerning the 17th amendment, the argument for its repeal absolutely centers around states' rights. If Senators are elected by elected reps and senators, they are more likely to defend their state against federal encroachments (upholding the 10th amendment), than they are if elected by the general population. Any federal program - ObamaCare, the financial reform bill, etc., - which increases burdens on state budgets would not sit well with Senators answerable to congressional bodies in their state.
Greg Halvorson