Hi from France where we have the same far right problem, I find it quite dangerous to dismiss them by saying “the AfD can achieve nothing”, it is only a matter of time.
We have the example of the National Front (now called the Rassemblement National) in France, showing that they can gather a majority of the votes and are quite significant, they started as a tiny party and grew when they decided to show a more mainstream facade.
I find it safer to overestimate the threat posed by the far right, rather than consider them too insignificant.
This is a global threat, and Europe once more is in danger, I’ll let the US deal with there own fascists.