Robert Paxton says that fascism is
"a form of political behavior marked by obsessive preoccupation with community decline, humiliation, or victimhood"
Fits Trump and the modern GOP to a tee. Literally everything from his slogan, to his rhetorical style and political obsessions is about America being in decline and everybody mocking the US.
Also fits Trump. His movement is rhetorically populist, yet are perfect running dogs for the traditional elite, as they cut taxes, deregulate and stack the courts with Federalist society judges who can't wait to turn the US into a perfect corporate dreamscape, which is a nightmare for everybody else.
Gerrymandering, stacking the census,
thugs hanging around polling places, trying to destroy the post office just to divert some ballots, open embracement of the Electoral College, voter id laws, and using felony disenfranchisement to target activists.
Internal cleansing, absolutely. Muslims and Mexicans are enemies. And Democrats are considered to be traitors and scum for daring to oppose Trump in anyway. You don't have your supporters wearing these shirts in a healthy rhetorical space.
The only weak point of this is an external expansion and even than Trump does have an obsession with buying Greenland, for no reason but it would look nice on the map. But that tracks considering that European fascism involved smaller countries, while the US has vast tracks of land, it already barely uses.