There are a number of factors which explain why Hitler became chancellor in January 1933. However, any of the factors, on their own, would not have individually resulted in his appointment. They are all linked in a web of causation and if any of the factors were missing, Hitler may well have not been appointed chancellor.
However, through saying this I feel that one of the most important factors as to why Hitler was appointed in 1933, was the depression, which then leads to the key factor of the Nazis electoral success. The depression derived from the Wall Street Crash, when people rushed to sell their shares because they realised the companies were doing badly. Thousands of businesses and people were ruined. This affected Germany because America withdrew its loans and the German economy collapsed. Millions were left unemployed. The new Weimar government broke down and people were ready to listen to groups like Hitler's Nazis, who promised a strong government and a better way of life. …
