Even the American Spectator has noticed that the MoveOn crowd and the Democrats are scared to death that Hoffman could win the NY-23 race.
Because they think it will inspire and empower the "Palin wing" of the Republican Party, and this is bad news for them. They might pretend, and have their media outlets say, that only moderate and "open tent" Republicans can win elections, but they know this is untrue.
Democrats are not afraid of "moderate" Republicans precisely because they know they can beat them. They are very afraid of conservatives, though.
Conservatives can win by being conservative and not pandering to the dead rodents in the middle of the road.