I don't think you can have it both ways. For Berman, if the structural variables that were present in the Interwar period in Europe --- countries in physical ruin after WWI, extreme economic crisis, including the Great Depression, the breakdown of traditional hierarchy, especially aristocracy, absent the consolidation of democratic regimes --- were present today, we'd see the return of fascism.
She doesn't say in so many words, though. She only goes so far as to say that Trump and European "right-wing extremists" threaten current democratic norms and should be challenged, lest they threaten the democratic order.
See for example, Berman's piece from the November/December issue of Foreign Affairs, "Populism Is Not Fascism," and especially the conclusion:
The best way to ensure that the [Marine] Le Pens and Trumps of the world go down in history as also-rans rather than as real threats is to make democratic institutions, parties, and politicians more responsive to the needs of all citizens. In the United States, for example, rising inequality, stagnating wages, deteriorating communities, congressional gridlock, and the flow of big money to campaigns have played a bigger role in fueling support for Trump than his purported charisma or the supposed authoritarian leanings of his supporters. Tackling those problems would no doubt help prevent the rise of the next Trump.Actually, democracy is not in trouble.
History also shows that conservatives should be particularly wary of embracing right-wing populists. Mainstream Republicans who make bogus claims about voter fraud, rigged elections, and the questionable patriotism and nationality of President Barack Obama in order to appeal to the extremist fringes are playing an extremely dangerous game, since such rhetoric fans citizens’ fear and distrust of their politicians and institutions, thus undermining their faith in democracy itself. And just like their interwar counterparts, these conservatives are also likely enhancing the appeal of politicians who have little loyalty to the conservatives’ own policies, constituencies, or institutions.
Right-wing populism—indeed, populism of any kind—is a symptom of democracy in trouble; fascism and other revolutionary movements are the consequence of democracy in crisis. But if governments do not do more to address the many social and economic problems the United States and Europe currently face, if mainstream politicians and parties don’t do a better job reaching out to all citizens, and if conservatives continue to fan fear and turn a blind eye to extremism, then the West could quickly find itself moving from the former to the latter.
Donald Trump is not an "also-ran" but the president-elect who will take office as the 45th president of the U.S. on January 20th.
Berman's problem, I would argue, is that she sees populist rejection of left-wing policies as threats to democracy. They are not.
Her other piece, which specifies the nature of fascism much better than at Foreign Affairs, is at Vox, "Donald Trump isn’t a fascist."
The always excellent Sheri Berman: Trump is a right-wing populist, not a fascist. https://t.co/CyQgOcBQcH— Daniel Nexon (@dhnexon) January 3, 2017
It's good, but like I said, Berman fails to persuasively explain why so called "extreme" right-wing populist movements threaten democracy.
These movements, at least in the U.S., don't even threaten democratic norms, and her examples (like Trump's rejection of intelligence findings on Russian hacking) aren't in fact cases of deviations from such norms. And of course, the same things that Berman claims right-wing populist are doing, like rejecting election results, are exactly what Democrats and leftists have done since the election. So, why aren't far-left movements, socialism, neo-communism, and anti-neo-liberalism, in fact threats to democracy? The reason is that leftists have double-standards, and for them threats to democratic norms are only seen when populists reject leftist policies.
Until Berman and others can offer an even-handed argument for fascism vs. right-wing populism (or left-wing populism, for that matter), their commentary and research will be rejected as nothing more than partisan hackery.