How popular was the Nazi regime?

Very popular... seeing as 44,461,278 German people voted for the NSDAP party out of 45,453,691 voters.

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Without the date of the election, this statement says nothing about popularity. The most the NSDAP got in free elections was 37% of the popular vote (in July 1932). By May 1933 all other parties were banned in Germany, and elections became meaningless.