I know that there were a wealth of reasons for the Nazi party's rise to power in the early 1930s, but I find it common among liberals in the US today to blame "appeasement" (which I think is mostly people confusing the tactics of the international community in the late thirties with the domestic opposition within Germany). But I am curious: I know there was obviously lots of opposition to the Nazis from everyone from communists to Social Democrats, with brownshirts and communists often brawling in the streets, which leads me to ask...
Do you think any of the opposition groups had effective tactics, and that perhaps if these tactics had been more widely adopted, it might have prevented the Nazis becoming the largest party in the Reichstag? If so, which groups and what tactics?
As a corollary, are there good resources to look at that might shed more light on this or effective oppositional tactics to authoritarian or extremist parties in general that might be interesting to look at?
It's not exactly what you're after - I don't have the kind of detailed knowledge of pre-1933 German politics your question requires - but you may be interested in this answer of mine, which discusses the success of anti-fascist movements in the 1930s, and links to some older discussions on a similar theme.