Hitler's ascension to power was perfectly legal under the democratic Weimar German Constitution. The legal architect of that ascension was a man named Carl Schmitt.
Was there democracy under Hitler? Well, he held plebiscites and people voted.
Nazi Crown Jurist Carl Schmitt escaped punishment at Nuremberg and his writings have undergone a huge revival and are feverishly studied by both the Neo-Cons and Antifa.
How close are we to a 'Schmitt' government today?