I have a fondness for German Expressionist films from the 20s and 30s. I've sporadically wondered how to make a timeline where it is a continuous staple genre with a typical subject matter rather than something which is primarily an aesthetic. I've usually thought about this in terms of ensuring it stays alive in German cinema and then ensuring German cinema isn't completely outclassed by American cinema. A CP victory might create a Germany with more cultural influence and soft power, but may preclude German Expressionism if it strengthens German cultural conservatives. A surviving Weimar might be a possibility, but its international cultural influence is not assured.
I'm looking for a continuous presence and a German one, not a revival a la Tim Burton.
Any ideas on how this could be done?