Are the Liberal Democrats Weak or Stupid?

Red Brick blog publishes a diatribe against the Liberal Democrats for agreeing to all kinds of viscous policies on housing and benefits without a mandate or even any explicit deal with the Tories.  This critique puts Sarah Teather in a curious light.  Having been part of a government that supported policies she regarded as immoral, she is now trying to backtrack.  Is her attitude better described as immoral, hypocritical or just a cowardly attempt to save her seat?