On the free speech question, it’s interesting to consider that the Weimar Republic actually had hate speech laws, along with stricter laws against obscenity and libel than what is the norm in most Western countries today. Weimar also had gun control laws, along with anti-fascist vigilantes that were regularly engaged in not only brawls but also gangland-like shootouts with the NSDAP-affiliated groups. Both the KPD and the SPD had their own private military armies just like the brownshirts, and the KPD was receiving support from the Soviet Union. None of that prevented the Nazi coup. As the CATO Institute explains:
“In my research, I looked into what actually happened in the Weimar Republic and found that, contrary to what most people think, Germany did have hate-speech laws that were applied quite frequently. The assertion that Nazi propaganda played a significant role in mobilizing anti-Jewish sentiment is irrefutable. But to claim that the Holocaust could have been prevented if only anti-Semitic speech had been banned has little basis in reality. Leading Nazis, including Joseph Goebbels, Theodor Fritsch, and Julius Streicher, were all prosecuted for anti-Semitic speech. And rather than deterring them, the many court cases served as effective pubicrelations machinery for the Nazis, affording them a level of attention that they never would have received in a climate of a free and open debate.
In the decade from 1923 to 1933, the Nazi propaganda magazine Der Stürmer — of which Streicher was the executive publisher — was confiscated or had its editors taken to court no fewer than 36 times. The more charges Streicher faced, the more the admiration of his supporters grew. In fact, the courts became an important platform for Streicher’s campaign against the Jews.
Alan Borovoy, general counsel of the Canadian Civil Liberties Foundation, points out that cases were regularly brought against individuals on account of anti-Semitic speech in the years leading up to Hitler’s takeover of power in 1933. “Remarkably, pre-Hitler Germany had laws very much like the Canadian anti-hate law,” he writes. “Moreover, those laws were enforced with some vigour. During the 15 years before Hitler came to power, there were more than 200 prosecutions based on anti-Semitic speech… As subsequent history so painfully testifies, this type of legislation proved ineffectual on the one occasion when there was a real argument for it.”
The maintenance of civil society, the vigorous defense of all civil liberties across the board (the ones outlined in the Bill of Rights and beyond), maintenance of a social and cultural consensus in favor of at least some bare minimum of democratic, libertarian, or egalitarian values, sanctioning those who engage in political violence (whatever their ideology) is the best way to prevent totalitarian/authoritarian groups (right, left, religious) from gaining genuine political power.