It is a shame the Lib Dems have fallen off their twigs so badly, they are hardly there at all.
Would you like to elaborate, Floo? How have they "fallen off their twigs"?
My impression - for what it's worth - is that there have been two factors in the apparent decline of the LibDems.
1 Some passionate LibDem supporters were appalled that they went into coalition with Conservatives. The part's "purity" was thus defiled.
2 Nick Clegg gave a promise that student fees would be abolished.
My own view is that, in the first instance, this (a) provided the party with a valuable experience of political power and (b) did - to some extent - modify the activities of their Conservative partners. As the considerably smaller partner the LibDem's ability to influence policy was restricted. In the second instance, well, not achievable for a reason just mentioned.