Do you really believe that? Clegg had little option but coalition with the Conservatives, and it is clear the Lib Dems were a moderating influence. It is easy and cheap to blame the Lib Dems - what was the alternative?
A moderating influence? When? On the Bedroom Tax? On the austerity policies that Osborne enacted?
And of course he had an alternative. He could've bargained far harder with the Tories, like making PR mandatory, or he could've negotiated with Labour.
I'd take Nick Clegg a lot more seriously if he hadn't enabled half of that.