Is it wrong to call Bush a liar?

In Balkinization Jack Balkin replies to a Nicholas Kristoff op-ed piece in which Kristof warns liberals not to go off the deep end (as the right wing did with Clinton) by stooping to name-calling. Balkin reviews some of Bush's history and then writes, "at some point, the number of false and misleading statements becomes so great that you have to assume that some of them were deliberate. At that point, what word can one use?"