Ontrus

How often does it happen that the police gets infiltrated itself?

You did not ask me, but I'll tell you as a German: Absolutely not.

The partition was viewed as a tragedy by people on both sides. What especially worried many was that in case of a war you'd be ordered to fight your brothers on the other side. Also, East Germany prohibited visiting relatives and exchanging information. You probably heard of the Berlin Wall built to keep citizens from escaping. Formally West Germany never even acknowledged that East Germany was another country while being accepting every of their citizens that managed to flee. Every political party apart from the Greens supported reunification. There was no controversy about that.

Immigration wasn't a big issue at all back then except for the vague idea of kicking out the Jews. Hitler mostly got elected because of an economic crisis and the Versailles treaty, both of which were unsolved by the Weimar republic that could hardly prevent civil war.

When Hitler came to power, it was absolutely clear there'd be a dictatorship and the abolition of democracy. His party was unabashed about it and there had been a coup attempt about a decade earlier already. Yet a lot of people did not mind and thought it might actually be better since democracy had failed so badly.

People stating why they voted for Hitler in German, recorded in 1983 (a different time, obviously).

For German-speakers, an article from 1960 when this "Kameradenerziehung" still existed.

If you speak German, you can look up the Green party's own explanation some time later, otherwise maybe try Google Translate. Yet I think they are whitewashing quite a bit.

I personally strongly dislike the party, since imho it frequently screws up by their insistence on ideological purity without much care for the actual outcomes of their ideas (i.e. I am biased, perhaps) :p So take it as a personal opinion and think for yourself:

A lot boils down to leftist hatred of Germany as a nation and dislike of capitalism. Some members flirted a lot with socialism so much that they thought East Germany's economy and society in general had a lot going for it and saw the Western government as "Faschists" occupying the GDR and destroying hope for a better (or alternative) future there. You might be familiar with the old tune of every Communist failure being excused as "not real socialism/communism" or "only in transition". That was pretty much the case here. So much that even the extreme authoritarianism and environmental destruction (both things the party ideologically claims to oppose) were ignored. Sympathies with a state that shoots people trying to flee, rigs the elections, lets schoolchildren throw handgrenades and sing war songs, jails political opponents, runs a massive spy network against the people, censors the media -- no, that does not leave a good impression on their real values on me.