Nominating Nebraska Gov. Mike Johanns for agriculture secretary strikes me as not the best idea from a GOP party-building standpoint. It removes the Republican with the best chance of defeating Sen. Ben Nelson in 2006. At this early stage, at least one poll looked very good for Johanns. Perhaps Johanns told the White House he wasn’t intending to run. But if he was at all serious about the bid, he won’t be making it now–and GOP prospects for 2006 look a little bit worse.