It's come to mean "repressive," or "really bad," or "dictatorial." If a teenager's parents won't let him use the car, the are not fascists. Nixon was not a fascist. An authoritarian regime, or a government created by a military coup is not necessarily fascist...it has to have a special social history and set of policies to be fascist. It can be really repressive, even murderous, but not fascist.
Trump does have a whiff of fascism about him--he's got the leader cult thing going and the racist, nationalist mojo working for him, and makes an appeal to the fears of white people who have seen their standard of living fall and whose superior status over blacks has eroded to some degree, while they still are less likely to be jailed or killed by cops or face job discrimination.
One trait of fascism is an aggressive, expansionist militarism. Neo-con supported Hillary Clinton fits this trait more than Trump. He's actually more of an isolationist.
Anti-semitism has often been cited as a necessary component of fascism. But fascist ideology and fascism coming to power began in Italy. The word fascist is derived from fasci, a bundle of sticks bound together that was a symbol of authority in ancient Rome (an individual stick can break, but bound together it creates an unbreakable unity). Hatred of Jews was not part of fascist theory or practice. Many Italian Jews were members of Mussolini's party. It wasn't until WWII was well underway that Hitler pressured Mussolini, as his junior, dependent partner, to crack down on the Jews.
The USA has had plenty of xenophobic, rightist populist, racist movements and politicians from Tom Watson in the Reconstruction period in the defeated South, to anti-Chinese immigrant movements, to the KKK revival in the 1920s,which was mainly about stopping the flow of Southern and Eastern European Catholic immigrants. These kinds of movements are as American as apple pie. And many of them have had sponsorship from establishment elites, not just from lumpen elements or downwardly mobile workers.
What is fascism?
Fascism begins as a social movement among outsiders. It does not come from above, from the standard ruling class circles -- landowners, large capitalists, the church or the army. It needs a deep economic crisis, the kind that rocked Italy and Germany after WWI. It also needs a political crisis: an ineffectual government that is seen as being unable to cope with mass destitution and misery.
Mussolini's base of support came from those were ruined by the results of the war and from masses of unemployed, demobilized soldiers, who became the backbone of his shock troops, the Fascisti. He took power in 1922, eleven years before Hitler. Germany also faced a political and economic crisis and the NAZI party recruited from the down and out ruined farmers, artisans and workers.
Neither Hitler of Mussolini ever won an election. Their candidates never got close to a majority. How did they come to power? They were large movements, but there were other parties that had more followers, all from the left. So what happened?
In both cases a strong enough section of the ruling class were panicked about the future and fearful of a Communist/Socialist take-over that they threw their support to the fascists marching in the streets.
A fear of leftist social revolution on the part of the ruling class was needed to motivate them to turnover political power to otherwise disrespected lower class thugs like Hitler and Mussolini. Also aiding the fascist take-over was the vacillation and confused policies of the leaders of the mass Communist and Socialist parties.
Does an analogous situation exist here in 2016 USA? Where is the dire threat from the left, besides nowhere? Fascist movements have always needed a big assist from part of the ruling rich to take power. The core of the ruling class here does not want Trump. They prefer Clinton. The economy isn't great, but it's a million miles away from anything like 1922 Italy or 1933 Germany. Wall Street, the Pentagon, the national security industry are not being pushed to the wall, shaking in their boots. The charade of elections and democracy is still working and it would be folly for the rulers of America try to set up a dictatorship and especially to hand over power to a clown like Trump.
If Trump were to win the election, it still would not be fascism. It would be an incompetent, infantile jackass as president. That's happened before. The real powers in this country wouldn't allow him to do much of anything, or maybe not allow him to finish his term. He would do damage, but it would be the same damage that both Democrats and Republicans have done before: Reagan's consolidation of a white supremacist Republican party; the Clinton's deregulation of Wall Street; regressive tax policies; Bush's wars and Obama's continuation of these wars.
The actually existing threat to democracy has come from what Gore Vidal called "the national security state," that began under President Truman with the start of the Cold War. There have been no raving demagogues in the streets whipping up the masses to build the network of domestic spying and creation of agencies that, could, if called upon by the ruling rich of this country, squash free speech and impose martial law. The national security state comes naturally from the Democratic and Republican duopoly than manages the affairs of our predatory imperialist nation.