Hitler made promises that they found believable and he appealed to their sense of national identity and he followed threw with his promises to create more jobs and bring the German Economy back from virtual bankruptcy. He restored their faith in their country and produced many amazing projects that showed the Germans that they could be proud of themselves and of their country, and they stopped feeling that they have no future. So we can say that Hitler create a sens of belonging to the society. So many Germans were happy to support him Hope this Helps :D
