The main reason the Nazi party gained popularity in the 1920s and early 1930s was due to Hitler as a charismatic and effective leader.

Indeed, Hitler's charisma and effectiveness as the leader of the NSDAP contributed to their increasing popularity in the said time period. However, it is more accurate to state that the economic depression following the 1929 Wall Street crash was a more significant factor in causing the NSDAP to gain popularity. Mainly, this is due to the fact that the depression in Germany caused mass poverty and thus made the general public more sceptical of the weimar government. By 1932, 6 million people had become unemployed due to the depression. In the 1930 federal elections, the NSDAP gained 23 seats in the Reichstag, and by 1933 had become the dominant party with 43% of the vote. This rapid increase in popularity can be connected to the depression of 1929, and thus arguably without the depression such an increase in voting for the Nazis would not have occurred. However, one could argue that while the depression made the public sceptical of the Weimar government, it still required an effective leader to exploit the opportunity. Yet, this argument is refuted by the fact that Hitler had been the leader of the party since 1922, and only after the crises did the NSDAP gain such a large amount of votes.