Ok - Germany gave up gun rights after World War 1. Then, fast forward to Hitler. Prior to World War 2, Hitler made it ok for one group to have guns and not another group (the Jews). Hitler then did what - a Holocaust where unarmed Jews couldn't fight back.
Now let's compare that with today. The Democrats are trying to get guns out of the hands of people, normal law abiding citizens that aren't shooting up schools or their neighbors.
So let's say they win and guns get banned. Now, only the armed forces and police/sheriff forces have guns right? Nope. Criminals still obtain them illegally. So now, American citizens have to worry about criminals who have guns, while they can't have a gun to protect themselves.