What's the difference between Rachel Maddow and Keith Olbermann as opposed to Sean Hanity and Brit Hume? Rachel Maddow nails it in this interview with former Bush speechwriter, David Frum.
Frum comes on Maddow's show to say that the attacks coming from the McCain camp are hurting the country, and by the way, your show, Rachel, is doing the same thing. In the ensuing discourse it becomes clear, to those who weren't sure of it already, that Rachel Maddow is a heavyweight. She stays calm, holds her ground, stays on topic and embarrasses Frum (look for his downcast eyes - he knows he's beat).
But this discussion highlights a bigger, maybe the predominant, trend in today's national politics, especially since 2000. Democrats attack Republicans on issues of policy, experience and competence. Republicans, needing a response, and unwilling as always to defend themselves (After Katrina: "We're not going to play a blame game;" in the financial crisis: "When the house is on fire, you don't want to talk about how it was set."), have to find a way to counter-attack. Since, for the most part, they can't attack on policy matters, both because they've been doing such a crappy job and because the Democrats have been in opposition, they have to resort to personal attacks.
There are legitimate different approaches to policy between the Dem's and the GOP (the role of military force, the allotment of power to federal, state and local governments, etc.), and we see some discussion of them between the campaigns (albeit more from the Obama camp). When personal attacks are made, the Democrats, and Olbermann and Maddow, point to personal shortcomings that are relevant to the capacity to lead (involvement in political scandals, temper, competence), where Republicans and their supporters in the media seem to be simply grasping for any mud they can find (Clinton's voice makes men's balls shrivel, Obama is a terrorist), because it's all they can do right now.