There is an expression in Berlin: "the more east you go, the more east you are". Would it be phrased "je östlicher du gehst, desto östlicher bist du"?
There is an expression in Berlin: "the more east you go, the more east you are".
No, that is not an expression in Berlin. I've never heard it and I've lived several years in Berlin.
The article says
The general whispered rule in Berlin is, the more east you go, the more east you are. The Berlin wall didn’t come down that long ago. The further east you go, the more shaved heads you’ll see, and the more Dr Martens.
but means: "the more to the east you go, the more right-wing/ nationalist the people are"
As "east" is on the right side of a map, I get want the author tries to say, but it doesn't make sense in German (and neither in English I think).
In German I would say:
Je weiter man auf der Karte nach rechts geht, desto rechter sind auch die Menschen.
Der Osten Berlins wählt rechts.
If you want to know more about the development of right-wing voting in Germany, I can recommend this article and map: https://interaktiv.morgenpost.de/wo-deutschland-rechts-waehlt/