I think you can go with this in a variety of ways. Obviously, I think that one of the most direct ways would be to try to call attention to the fact that Hitler and the Nazis do not provide the best answer to Germany's problems. This might involve you writing as a supporter of Weimar democracy and the idea that Germany's fragmentation can be addressed if all parties are seen as active stakeholders in the process. Indeed, you might borrow a sentiment from the Nazis in suggesting that the Versailles Treaty was harsh. Yet, it only underscores the importance of all parties in Germany coming together and seeking to build consensus across the board. I think that you would probably speak out against the scapegoating that Hitler was able to bank much upon in terms of tapping into German resentment.
Perhaps you would argue that German nationalism can be demonstrated without the demonizing effect of targeting individuals. I think that a political opponent of Nazism would be arguing that German history does not have to trade off with individual rights. In the end, you want to assert as a political opponent of Nazi Germany that the Nazi approach will do more to isolate and target Germany than raise it up. There can be a way for German consensus to be demonstrated without the element of targeting those who are different in order to consolidate power. It is a difficult position to articulate because few in Weimar Germany genuinely understood the threat that Hitler posed until it was too late.