“The thought of having to face this is blinding,” a Democratic senator said in an interview, asking for anonymity to speak candidly about the prospect of Reid losing his tightly contested race against Republican Sharron Angle.

But the majority leader race would very likely be just the beginning of a top-down leadership shakeup after the elections.

If Murray loses her reelection bid to Republican Dino Rossi, there would be a race for her No. 4 leadership position as conference secretary. But there’s no clear heir apparent for the position.

Going down the line, retiring Sen. Byron Dorgan of North Dakota is relinquishing his position running the Democratic Policy Committee, leaving another opening in Democratic leadership.

And then there’s the campaign committee.