Don't forget the Hitler enabling German Centre Party.
Well, it is true that the German Centre Party shifted rightward under prelate Kaas and that its support resulted in the Enabling Act of 1933 getting the necessary 2/3 majority.
It is also true that the German Centre Party was started as a clerical/SoCon reaction to cultural "liberalism" (separation of church and state, civil marriage, secular education).
That being said from the standpoint of political arithmetics the Centre Party was really in the centre of the political spectrum for most of its existence. The Centre Party was part of the democratic and republican forces (together with SPD and DDP) during the Weimar Republic (at least until about 1932). The people that are to blame most for Hitler are the conservative establishment of the time (Hindenburg and his kamarilla, the intrigue-spinning Schleicher and von Papen and the reactionary big industrials).
The (defunct) German Centre Party is actually a quite good example for a party that occupies a spot in the centre of the political spectrum (without actually being centrist in the proper sense...)
I dispute that there's any 'proper sense 'of centre. Centre must fluctuate with time and place or else you wind up like those poor fools at Political Compass calling the entire western world right wing. The Roundheads and Cavaliers would be be hardcore rightwing traditionalists if you transported them to the present for example.
Far better to adapt the definition to the context being discussed. Weimar Germany's political spectrum ran roughly from anti-democratic left to anti-democratic right. Within that context Centre is well, quite centrist.
