This interests me. The AP reports that, amidst a sea of Republicans being caught in the Abramoff scandal, there are also connections to North Dakota Democrat Sen. Byron Dorgan. Now, we should of course be wary of who's making these accusations, but let's say that Dorgan is indeed illicitly involved in this sordid affair. Partisan Democrats would thus be faced with a choice. Try to shield Dorgan, and blunt the effectiveness of the "Culture of Corruption" attack they've been making against Republicans; or, let Dorgan swing and lose a wildly popular Democratic Senator in blood-red North Dakota. While obviously it isn't a straight shot "principled or partisan" issue (Democrats could politically conclude that the benefits of keeping the focus on corruption outweighs losing a red-state Senate seat), it is a good indicator of how serious the partisans are about corruption in government. Right now, voters see little difference between congressional Democrats and Republicans, suggesting that they haven't internalized the message that Democrats are any more anti-corruption than the GOP is. An unequivocal stance of zero-tolerance could change that.
As such, it's heartening to see DKos not hesitate for a moment: "I'm not interested in nuance on this issue. If Dorgan becomes collateral damage, then so be it."