Fascism is a term commonly used as an epithet for any ideology that a person doesn't like. Nevertheless, it is a real political phenomenon which can be defined (if with some difficulty) according to particular characteristics. When we look at what fascism really is, we discover that it is not something which must be limited to Germany and Italy of the mid-20th century. It is, instead, a phenomenon which might conceivable occur in any nation at any if the conditions are right. America is no exception.
Robert O. Paxton, a professor emeritus at Columbia University, defines fascism in his book The Anatomy of Fascism as: "A form of political behavior marked by obsessive preoccupation with community decline, humiliation or victimhood and by compensatory cults of unity, energy and purity, in which a mass-based party of committed nationalist militants, working in uneasy but effective collaboration with traditional elites, abandons democratic liberties and pursues with redemptive violence and without ethical or legal restraints goals of internal cleansing and external expansion."
It should be clear that there is nothing fascist about "Islamofascism," so that's an example of people using the fascist label as a means of attack rather than as a serious description. Fascism is more like a religion than it is like a political movement. Fascism isn't motivated by rational conclusions about economics, political philosophy, or social policy. This makes real religions like Christianity well suited for integration with a fascist movement. If fascism occurs in America, it will be Christian in nature because only Christianity has the power to motivate a mass-based movement with a passionate concern for unity, redemption, victimhood, and nationalism. Christian fascism will also be convinced of its own righteousness, moral purity, and godly intentions.
This image was taken from a World War II poster of an American prisoner of war saying "Don't Let Me Down" and "You are still free to work." Americans are free to work, but how free are they to enjoy the rest of the liberties which Americans fought and died to protect in World War II? Overt repression in America hasn't started, but once a people unjustly puts others in shackles, they put on their own shackles as well. One is imprisoned by the brutality of the other; the latter is imprisoned by the need to perpetuate their own brutal methods lest the repressed rise up.