The years 1924-1928 were a critical period in the development of the Nazi party and for the man who would become its leader, Adolf Hitler. There are really two reasons why support for the Nazi Party declined and first of these is the Munich Putsch. This was an attempt made by Adolf Hitler to instigate a revolution in Munich but it proved to be a catastrophic failure. The Nazi Party was banned, Hitler was arrested and prohibited from speaking in public.
Another reason why the Nazi Party declined in support in this era was due to Germany's prosperity under Gustav Stresemann. The Dawes Plan in 1924 gave Germany longer to pay their reparations to America, Stresemann brought inflation under control and negotiated Germany's membership to the League of Nations. Even better, Stresemann borrowed millions of marks from America which he invested in Germany's infrastructure, providing a much-needed boost to the country's economy.