Koz’s point is well-taken. The exit polls on Election Day, 2010 are unlikely to show that Rangel’s ethics cost Democrats control of the House. But corruption matters, especially among the independents who often hold the balance of power in competitive elections. Republicans undoubtedly lost control of Congress in 2006 largely because of the unpopularity of the Iraq war the reverberations from Hurricane Katrina. But the ethical lapses of Tom DeLay, Duke Cunningham, Robert Ney and Mark Foley didn’t help. They may even have hurt Republicans enough to cost them the marginal seats that made the difference.“[T]he Rangel problem is not the big worry for the D's. The D's problem [is] their various health care bills and they way they've tried to get it through Congress, ie all inside game and no outside game. Charlie Rangel is an order of magnitude smaller problem.”
Corruption should, if anything, be more damaging to the electoral prospects of liberal Democrats. Conservative Republicans are happy to live with the distribution of benefits and burdens that emerges from relatively unregulated markets. Liberals want to expand the purview of democratic government, and therefore the occasions for honest mistakes and less-than-honest self-dealing. Liberalism's attractiveness depends on the belief that the democratic process can function as a relatively efficient distributive mechanism. Corruption and political cronyism undermine that belief.
So if we assume that Charlie Rangel and Tom DeLay are equally corrupt and that every other pertinent variable remains the same, we should expect Rangel to do more damage to the Democratic brand than DeLay did to the Republican brand. All other things being equal, Rangel undermines liberal values more than DeLay undermined conservative values.