Jonathan Calder considers the decline of the Liberal Democrats in Adur:
Checking the relevant page on Wikipedia I find that, remarkably, the Alliance and then the Liberal Democrats had uninterrupted control of Adur between 1980 and 1999.
But something went terribly wrong after that. Today there are no Lib Dem councillors on Adur and a council by-election there this evening has no Lib Dem candidate.
He suggests that churn happens to areas as well as individual voters.