Samir Amin gives one kind of conventional listing of historical fascist regimes in The Return of Fascism in Contemporary Capitalism Monthly Review 66:4 (2014):
Political movements that can rightly be called fascist were in the forefront and exercised power in a number of European countries, particularly during the 1930s up to 1945. These included Italy’s Benito Mussolini, Germany’s Adolf Hitler, Spain’s Francisco Franco, Portugal’s António de Oliveira Salazar, France’s Philippe Pétain, Hungary’s Miklós Horthy, Romania’s Ion Antonescu, and Croatia’s Ante Pavelic. The diversity of societies that were the victims of fascism—both major developed capitalist societies and minor dominated capitalist societies, some connected with a victorious war, others the product of defeat—should prevent us from lumping them all together.Speaking of the period when "fascism" seemed easy to define, this article is interesting in a strange way, Not Chicago 1968, but Berlin 1932 The American Prospect 03/28/2016. When I started reading it, I thought it was just going to be a way to call Bernie Sanders a Commie. But it's actually a somewhat clumsy historical analogy about the need for Democratic unity after the primaries.
Jamie Galbraith in Inequality and Instability (2012) talks about "the uneasy coalition between working-class voters and elite contributors and candidates that characterizes the Democratic Party." I'm not sure the Wall Street wing of the party will be completely on board with Sanders as the candidate. And if Clinton should become the nominee, the conservative Democrats will have to work to earn the trust, much less the enthusiasm, of Sanders voters.