Might not they merely be saying, "Yes, but he's OUR liar now"?
They may actually believe that W lied; he never defended himself or blamed others, even if they were to blame. Classy? Maybe. Productive? NOT! He's why we're stuck with The 0 and his policies. (I can only grant that the media has SOME responsibility, since they are willing to spread and champion Dem lies but completely unwilling to speak or defend Repub truths.)