How did the German government under the Nazi rule build support among the German people?

Hitler had become massively popular through intense rallies and promises of a greater Germany.

Explanation:

He had started the Autobahn Project in his early career when Germany was facing the Great Depression. This employed many citizens to work on the first highway system in the World. He had also implemented Health care and Welfare programs in Germany. In 1936 he had also shown the power of this new Germany to the World in the Berlin Olympics by creating a massive stadium still used today and bringing back Athenian-Olympic traditions. Later he would successfully incorperate Austria, Sudetenland, Memel, etc into Germany.

c holding free elections