Shelley Moore Capito, the House Republican from West Virginia who, under the special election law to replace the late Robert Byrd could have run for her House seat and a Senate seat at the same time, has decided not to use that privilege, according to sources with the Washington Post’s Aaron Blake. This virtually assures that Gov. Joe Manchin will be the next Senator from West Virginia.

The one poll released on a hypothetical Manchin-Capito matchup, from Rasmussen, showed Capito losing by double digits. She would have options in the future, with the Governor’s seat up – and Manchin out of the way – in 2012, and Jay Rockefeller potentially retiring in 2014. But the quick-strike nature of the special election proved unattractive to Capito, even though she would not face the risk of losing the House seat.

Given this turn of events, it’s all the more puzzling why Democrats gave away the store in the negotiations over the special election, other than the fact that they felt confident that Manchin would bulldog everyone else out of the race.

The deadline for announcing for the special election is Friday. Manchin has already made himself a candidate.