Lots of things can stop them, and lots of things can stop the far left. Many things already are.
Extremists by definition are outliers in every population, in every society throughout history. Even at the height of facist power in 1940 fewer than 10% of Germans were Nazi party members. Current best estimates for the US are that 6% of the population identifies as “devoted conservatives” on the right, and about 8% with more left-leaning “progressive activists” -
https://hiddentribes.us/
And within those small groups, the percentage of armed militant extremists is even more tiny – at most 20,000 or just .006 of all Amercans -
https://www.nytimes.com/2020/09/11/us/politics/veterans-trump-protests-militias.html
But why then does it feel like the true majority of moderate, rational, average citizens who just want good government and a fair shot at a better future are outnumbered and losing the game ?
Because whenever radical factions want power they try to gain it by distorting public perception and burying the truth :
“A key reason is that polarization has become a business model. Media executives have realized that they can drive clicks, likes, and views, and make money for themselves and their shareholders, by providing people with the most strident opinions. This means that the most extreme voices―no matter how outlandish―often get the most airtime. In addition, people with the most extreme views are often the most certain of their positions. They are willing to argue with anyone and avoid moderating their opinions or conceding points to the other side.”
- Hidden Tribes, 2018
But political parties follow the same “business model” too, whenever they use partisan tactics to politicize the judicial system or gerrymander voting districts to prop up fake majorities. And it all got so much easier when twisted laws started treating money and free speech like the same thing.
So how do we stop fascists, or anarcists, or any other extremist ideaology with no legitimate right to power ?
• Stop being scared.
• Stop being fooled.
• Start acting like your ideas and values matter.
• Start confronting lies, and corruption, and hate.
• Start demanding that those in power respect democracy, and are held accountable when they don’t.
• Start acting like decent, tolerant, fair minded human beings are in the majority.
Because we really are.