I don't think harking back to Nazi Germany and the atrocities that happened will get your point across. For many right wingers their approach, starting with arm-bands and ending with full blown uniforms, would be too attractive to their minds. It's too civilised and orderly for what is happening today. When a large proportion of the people are willing to wear MAGA hats and chant Trump, Trump, Trump as they march along, the similarities are too close for comfort.

A better analogy would be to compare what is happening in the US to the Taliban. An aggressive, heavily armed minority with fanatical religious beliefs, who want to impose their own version of morality and law on the masses. They don't wear uniforms and they wage wars from the back of pick-up trucks. They win by terrorising the local communities, threatening death and destruction to any that oppose them. The oppress women under the guise of religious morality.

The Taliban could not be defeated because they were part of the Afghan culture and integrated into the general population. It is difficult to defeat an enemy that looks like a friend and is related to your family. Even when the Taliban were almost driven out of the country, they returned with speed as soon as the circumstances were right. Does all this sound familiar to you.