The National Socialist German Workers’ Party (NSDAP), founded in February 1920, ...
Don't confuse this party with with either of the following two parties which evolved in 1918, each of which has a similar name (but with a different ordering of the constituent words):
This article, dated 30 January 2008, says:
In May 1928 elections, the NSDAP only managed 2.6 percent of the vote nationwide.
Hindenburg ... called for new elections on Sept. 14, 1930. NSDAP, until then a tiny splinter party on the national political stage, raked in 18.3 percent of the vote.
When elections were finally held again in July 1932, the Nazis got a whopping 37.4 percent of the vote.
General elections held in November that same year  showed a drop in support for the Nazis to 33.1 percent. Even worse for the NSDAP, President von Hindenburg still seemed disinclined to hand over power to Hitler, even though the NSDAP had received far more votes than any other party. He said that naming Hitler chancellor was "neither compatible with his conscience nor with his obligation to the Fatherland."
Help came from an unexpected quarter. Franz von Papen, who had already had his turn on the chancellor merry-go-round in June, wanted a second chance and beseeched von Hindenburg to give his backing to a coalition of Hitler's Nazis, independent conservatives, and the arch-nationalists from the DNVP. Other von Hindenburg advisors likewise pleaded for the solution, arguing that, by hemming Hitler in among those who had long been in Germany's political elite, they would be able to control the wannabe dictator. In January 1933, von Hindenburg gave in.
Hitler had made it -- but he was still far from the dictator he would become. Indeed, his first government only included two ministers from the NSDAP, Hermann Göring as minister without portfolio and Wilhelm Frick as interior minister. But he wanted more; priority number one for his new government was the dissolution of the Reichstag and, yet again, new elections. His goal was clear, and it was one shared by much of the country's political elite: Once the Nazis and their allies had a majority, the Reichstag was to hand over power to the chancellor. In short, Hitler wanted parliament to vote itself out of existence.
Once again, luck seemed to be on Hitler's side. On February 27, less than a week before the new elections, the Reichstag, Germany's parliament building, was set ablaze. The blame was pinned on Dutch bricklayer Marinus van der Lubbe, and indeed, after decades of research into the incident, no convincing proof has been unearthed to show that he wasn't acting alone. But Hitler, Göring and Goebbels knew a propaganda godsend when they saw one. "If this fire, as I believe, is the work of the Communists, then we need to crush this murderous plague with an iron fist," Hitler told his vice chancellor, von Papen.
And crush they did. The day after the fire, the "decree for the protection of people and the state" went into effect, allowing Hitler's Nazis to go after their political enemies with gusto. It was the wave of arrests set off by the Reichstag fire that ultimately made the rapid construction of prisons necessary. Many of those prisons would later become concentration camps.
On election day in 1933 -- the last halfway free elections to take place in unified Germany until 1990 -- the Nazis won 43.9 percent of the vote.
The result still wasnt enough for the party to control its own destiny. But by then, it was already too late to matter. When the fateful parliamentary session was called to order on March 23, 1933 at just after 2 p.m., fully 107 representatives from the Social Democrats and the Communists were missing. Many of them were behind bars, while others were too afraid to show up or had already disappeared into exile. Just to be on the safe side, the parliamentary president Hermann Göring elected not even to acknowledge the 81 seats controlled by the Communists, significantly reducing the number of parliamentary votes available to the opposition.
At 6:16 p.m., SPD leader Otto Wels stepped to the microphone. It was to be the final public defense of democracy in Germany before the country started down the path of genocide, war and ruin. Not long after Wels finished, and following an enraged speech by Hitler, 444 representatives voted for parliament to be stripped of power. There were just 94 votes against.
See this Wikipedia (English) article
See this Wikipedia (German) article (English translation)Events involving National Socialist German Workers’ Party: