It's clear that the author doesn't really understand what happened in Germany during that period. He has the data:
...representing 37.3% of the electorate, Hitler commanded the country’s largest political movement. Social democrats trailed with 21%, and the communists with 14%.
The problem with "democracy" there was a problem with the parliamentary implementation in the German government. 37% for the Nazis, 14% for the Communists, totals 51%. That meant that all of the other parties combined could not form a majority government; they had to have the support of one or the other. And the only one thing that the Nazis and the Communists agreed on was that the form of the government had to be changed.
Hence somebody had to bring in poison to the governmental punch, it was only a question of which kind. Article 48 enabled Hindenburg to govern in the absence of a majority in the Reichstag until the latter got its act together. It also enabled Hitler to fill those posts with Nazis under the twin whammy of an emergency condition declared as a result of the Reichstag fire and the Enabling Act that followed. And since those together meant that the Nazis ran the elections, there were no more fair elections.
That last point appears to have escaped the author: if anyone is a Nazi around here it's the people who have corrupted the halls of government with partisans and hijacked the election system. These aren't people who want to make America great again.
You will never hear the left refer to the Nazis as the Nationalist Socialist Party.