Not going to comment on contemporary stuff until I've worked through some interesting census stuff (more on that at some point), but on a few historical points...
I'm sure that Michael Portillo once thought that too Usually. The key word is usually
True o/c
I have to disagree here; in many working class areas (typically the sort that mirror closely areas full of "Reagan Democrats" in the States) 1987 was worse for Labour than 1983. What you had in 1987/92 was, on the one hand, the
final collapse of the once large traditional Working Class Tory vote in old industrial areas and a steady erosion of support amongst the professional section (especially in the public sector) of the middle class and on the other a big increase in Labour support amongst low-ish income white collar workers (much of which was taken directly from the Alliance). I think this is shown off quite well by the fact that after 1992 Hornsey and Cambridge had Labour M.P's while and Edmonton and Batley didn't (which seems as absurd now as it would have done a decade before 1992). In many respects voting patterns here were becoming much more American.