In 1929, the bottom fell out of the German economy after the New York stock market crash. In four years, unemployment leapt from 6.3% to 30%. No German family was spared. At a time when effective government was most needed, political tensions rose.
By 1930, Chancellor Heinrich Bruning knew he had no chance of gaining a parliamentary majority that would support his policies. His Weimer party won barely 40% of the vote. The government fell farther into the trap of political paralysis.
Meanwhile the Nazis continued their growth, earning nearly 15 percent in parliamentary elections, almost double their total two years before. For three years Right Wing politicians in parliament pursued an orthodox economic strategy of FISCAL RESPONSIBILITY and DEFLATION. As Hoover learned in the U.S., such policies only worsened the depression.
What happened in the streets was at least as important as what happened in governmental offices. As V.B. Berghahn put it, there was a "tense atmosphere of perpetual conflict." The Nazis had massive popular organizations. By the time elections were held in 1932, the anti-government parties won over 40 percent. The Nazis influence in the streets had grown to the point that its SA was the largest and most ruthless of the partisan "armies." The balance of power shifted from the moderates to the extremists, both Left and Right. The government was unable to maintain order on the streets so in 1933 politicians invited Hitler to become chancellor and to form a government.
Most conservative politicians assumed that they would be able to tame Hitler by bringing him into office then getting rid of him once the immediate crisis had ended. However, in conjunction with the more mainstream right-wing parties, Hitler controlled a majority in Reichstag. He used that majority to pass legislation that created the most reprehensible regime in history.
Excerpt from the Sixth Edition Comparative Politics (text book) by Charles Hauss.