Hitler wanted to be the head of a Nazi dictatorship but he had to go about it legally. The only way to do this was if Hitler had held a two-thirds majority of Reichstag seats, allowing him to create the desired dictatorship by amending the constitution. He tried to do this by persuading Hindenburg to call fresh elections within 24 hours of him becoming Chancellor.
Before the election happened in March 1933 the Reichstag Fire broke out which was blamed on the Communists. Hitler was then able to convince Hindenburg of a Communist plot to overthrow the state and is issued an emergency degree under Article 48 which allowed the police to hold people indefinitely in “protective custody”.
The result of the election was that the Nazi share of the vote increased from 33.1% to 43.9%, winning them 288 seats but this was still short of the two-thirds majority they needed. However they managed to get through this by first of all having the support of 52 Nationalists, secondly gaining the support of the Centre Party by promising to protect the Catholic Church and respect its values but mainly because Hitler used the February Emergency Degree to imprison most of the Communists and the Nazis took their seats, giving them the necessary majority. This allowed the Enabling Act to be passed, giving the government emergency powers for four years. With this power the Reichstag became useless and the Nazis had their dictatorship.
Even with all of this, violence did still play its part. The Nazis just dressed it up in a coat of legality. For example, while the traditional conservatives held all of the main posts of the government coalition such as the Foreign, War and Economic Minister. The Nazis had control over the police, Goering and Frick appointed thousands of auxiliary police officers, particularly from the SS and SA which gave them the ability to legalise violence against their left-wing opponents. The SS and SA had also been know for trying to intimidate socialist members in the Reichstag, considering they were the only party that voted against the Enabling Act.
On the outside the Nazis seemed a respectable enough party because they had to be. The Nazis were only members of a coalition government when they came into power, they were restricted in what they were able to do and did not have complete power. They appeared to be legal to advance their position while using some violence in the background. They even preferred to talk about a “takeover of power” rather than a “seizure of power”, to avoid any violent connotations.