Why are so many Democrats in Washington DC trying to start a witch hunt for Bush administration Republicans?

Democrats are getting very fearful of their failing polices and are in dire need of something to distract peoples attention from them. We have had to put up with them blaming Bush for everything that went wrong in this world for the last 8 years and now that method doesn't carry much weight since they control the oval office, house, and senate. In a nutshell they are just stuck in the "blame Bush" tactic.