The strange death of liberal democrat England

For students of British political history you will already appreciate that I have taken the title of my post today, from George Dangerfield's "the strange death of liberal England", a book which attempts to explain why the liberal party became the third party after the First World War and  is one of those texts which you have to read if you study the subject at degree level.  It is clearly ironic that after almost a hundred years not being in government the successor to the liberal party, the liberal democrats, having finally achieved a place in government are now being totally smashed viz polling support,crashing to 9% in recent polls; the conservatives by contrast are at least holding steady at 30-35% or their core vote, labour benefiting very well from the current government troubles. 

One of the big questions not being asked at present is not that this current government is unpopular (it would always be so) , but why has the liberal democrat vote imploded in such a short space of time. Remember this time last year "cleggmania" was giving the liberal democrats 30% plus in the polls. Now at 9%, they are doing about as well as the liberal party in the 1960s. Why is this so? Is it because the liberal democrats are really the party of protest and have thus been shrunk to their own core support, now that they have to make difficult choices? Is it because their support of the conservative party ? Or something else?

As an aside, why is it that the liberals are taking the brunt of the wave of unpopularity over the cuts? As Cameron might say "we're all in this together", except that the liberal seem to be taking more of "this" than the conservatives.

Answers on a postcard please...