Re: Stazi
One partial explanation is that extreme right and extreme left ideological views are currently leaving a vacuum in the sensible centre ground.
Not quite. The "sensible middle ground" stopped being "sensible" and became utterly corrupt in both the moral and the literal sense of this word. Clinton, Blair, Schroeder, Barrosso and Co have tainted the middle ground so badly in the eyes of Joe Averag voter that he is happy to give his vote to a Nut( with or without al).
Yes, we definitely have a vacuum in terms of middle ground, but not vacuum of morally corrupt Fast Tonies (of the Ice age and British politics fame), but people who have a middle ground policy (not middle ground market stall in the temple).
Until we have any people will vote for the Witch of the West or various Nut(al)s.