Black Tuesday for Democrats

Wow - do the Democrats have everything going their way: a big majority in the House, a filibuster-proof Senate, a wildly popular president in the White House, and about to seal the deal on the universally-popular national health care plan (or at least that's they say on the network news every night). That's why it's so puzzling that three incumbent Democrats have all decided to step down on the same day. Can somebody shed some light on this? How does it compute that these power-brokers would walk way now, of all times?

North Dakota Senator Byron Dorgan

Colorado Governor Bill Ritter

And Connecticut Senator Chris Dodd, who was running for president not too long ago. He must have really lost his desire for public service. Or maybe he was just listening to this guy.