The SA was the Nazi Party's original paramilitary wing. It provided protection for Nazi rallies & assemblies and disrupted the meetings of opposing parties.

Contrast with today: BLM protesters in Denver use violence to break up Support Law Enforcement Rally

https://www.foxnews.com/us/denver-back-the-blue-event-violence-black-lives-matter-mob-protesters-anti-police

The Gestapo was the official secret police of Nazi Germany. It was created by combining the various police agencies of Prussia into one organization. It was tasked with detection of Nazi enemies, neutralization of Nazi opposition & policing the people for commitment to Nazi ideology.

Contrast with today: Dems want to defund the various police agencies of the US & create community "Action Teams" or "Crisis Response Teams" which almost assuredly will be tasked with detection of Leftist enemies, neutralization of Leftist opposition & policing people for commitment to Leftist ideology