What should democracies do about parties that use elections and other democratic means to destroy democracy itself? One well-established, but not universally accepted, answer is to ban the party before it comes to power.

But what about individual politicians? Americans are heatedly debating that question now that various legal challenges have sought to disqualify former President Donald Trump from running for a second term, owing to his role in the Jan. 6, 2021, insurrection at the Capitol. The same question is also preoccupying Germans who want to stop the rise of the far right. One proposal would strip individual leaders of political rights while stopping short of banning the far-right Alternative for Germany (AfD) party outright.

Such measures are serious restrictions on the political process that should only ever be used as a last resort. But when an individual has a consistent record of agitating against democracy – even after plenty of warnings – disqualification from the democratic process is indeed justified. Otherwise, democracies place themselves in mortal jeopardy. As Nazi Propaganda Minister Joseph Goebbels infamously gloated: “This will always remain one of the best jokes of democracy, that it gave its deadly enemies the means by which it was destroyed.”

Recognizing this fatal weakness, the political scientist Karl Loewenstein, who left Germany when the Nazis came to power, formulated the concept of “militant democracy,” by which he meant a democracy that is willing and able to defend itself through prima facie undemocratic measures. His focus was on party bans, and his ideas proved influential in the drafting of West Germany’s democratic postwar constitution. In the 1950s, both the Communist Party and a neo-Nazi party were prohibited.

Loewenstein cautioned that his approach amounted to fighting fire with fire. Those who avail themselves of the militant-democracy toolkit must appreciate the risks. A democracy that defends itself by undemocratic means might well end up destroying itself. Just look at Turkey, which has always been far too quick to ban parties on the basis of ill-defined criteria.

Critics of militant democracy insist that if a majority wants to dispense with democracy, there is no saving it; and that if anti-democrats are in the minority, the system’s fate should be left to the political process. Either way, they oppose high-handed, quasi-technocratic official measures that might further alienate those who are already dissatisfied with democracy.

These arguments, central to political debates immediately after World War II, have now returned with a vengeance. In the United States, Trump has been provisionally removed from the ballot in Colorado and Maine, on the basis of the Fourteenth Amendment. And in Germany, the Basic Law not only provides for party bans but also envisages individuals forfeiting their political rights if they try to subvert democracy.

While four cases have been brought against individuals under Article 18 of Germany’s Basic Law, all have failed. But now there is serious talk of applying the same provision against Bjoern Hoecke, the AfD leader in Thuringia, where the party is officially classified as “right-wing extremist” and yet far ahead in polls for elections this fall.

In Germany and the US, a full party ban seems a nonstarter. In America’s de facto two-party system, banning the Republican Party would be tantamount to abolishing democracy (even if most of the party has embraced Trump’s anti-democratic behavior). In Germany, the AfD has gathered so much support – it now polls at around 20 percent nationally – that a ban would look like a weapon of mass disenfranchisement. This problem highlights a paradox: when anti-democratic parties are small, a ban doesn’t seem worth it; but when they have grown large, a ban doesn’t seem possible.

Other critics have framed the dilemma even more starkly. Where there is a consensus in support of democracy, militant democracy is possible but unnecessary (West German democracy probably would have been fine even without banning neo-Nazis and communists). But once pernicious polarization has taken hold, there will be no broad support for militant democracy, because politicians will worry that its tools will be used against them.

These points are well taken. But those who oppose militant democracy tend to idealize the alternative. They assume that there will be a clean political contest with a decisive result, and that another defeat for Trump would remove him from the national stage. Trump has made it abundantly clear that he will contaminate the campaign with racism and possibly calls to violence.

He is likely to claim victory regardless of the election’s outcome. If the result is close, he will cry fraud; if it’s a landslide against him, he will claim that the whole thing was rigged. It is dangerously naive to believe otherwise.

The same logic applies in Germany. Hoecke has been charged with using Nazi rhetoric, he regularly warns of a mixing of cultures, and he promotes conspiracy theories such as the “replacement” of Germans by foreigners, leading to Volkstod (dying out of a people). Having him in a campaign will not leave the political process unchanged; it also sends a message that, ultimately, a democracy is willing to tolerate figures who systematically incite fear and hatred.

Some counter that banned individuals become martyrs. But right-wing populists portray themselves as victims no matter what, including when they lose elections. Of course, no democracy should be casual about fighting fire with fire. But if a candidate has exhibited a clear pattern of anti-democratic conduct over time and doubles down after clear warnings, disqualification is justified, as it is for both Trump and Hoecke.

In the US, as in Germany, an individual ban would preserve voters’ ability to choose a nationalistic party that wants to permit fewer immigrants, defends traditional conceptions of family, and advocates tax cuts for the wealthy. If that is what voters want, they can still get it.

Jan-Werner Mueller

Jan-Werner Mueller, professor of politics at Princeton University, is the author of "Democracy Rules." -- Ed.

(Project Syndicate)