There were many factors that led to the Holocaust movement's beginning as well as its ability to become such a large-scale operation.
First, at home in Germany, there was much unrest with the people. The economy was in shambles as it could never recover from World War I and the harsh demands of the Treaty of Versailles. The Treaty of Versailles made Germany pay $33 billion in reparations. Meanwhile, it also put huge limitations on Germany's trade industry, causing even more economic troubles in Germany.
This dysfunctional economy gave an easy way for the Nazi Party to rise in Germany. When the economic and social conditions of a country are low, it is almost always much easier to drastically change from the current regime. At times like that, people are desperate and have nothing to lose, as they feel their lives and the conditions around them can only get better. Knowing this, Adolf Hitler and his regime were ready to bring his Nazi Party into power in Germany.
The fact that the United States, Britain, France, and other countries did not take Adolf Hitler's regime seriously at the start of his reign after his book, Mein Kampf, had revealed his plans for annihilating the Jewish population, also helped Hitler to survive for such a long period of time. Few thought his plan could truly be carried out and, by the time people realized that Hitler was sincere and truthful in his book, it was too late. The Nazi Party had already gained enough steam to put up a huge battle against anyone who stood in its way.