The Radical Republicans were the more egalitarian ones who wanted to destroy the planter-ocracy and redistribute the lands to the poor blacks (and poor whites too).
They don't seem really "fascist" to me, even though the "State Suicide Theory" is fairly radical.
Eh, the Radical Republicans wanted to help the blacks, but we also can't forget the idea of "waving the bloody shirt" and why that was such a good electoral strategy. Radical Republicans wanted to help blacks but they were also advocates of the "stomp on their throat" school of thought in regards to treatment of the South.
And now on to our main attraction...
1) The national legislature of the US incapacitated due to;
2) A far worse 9/11, leading to;
3) A far worse anti-Muslim/anti-Middle Eastern reaction, eventually accompanied by;
4) A government plan, either initiated by the government or approved with a blind eye, of relocation based upon the precedent of the concentration of Japanese-Americans in WWII.
I find this difficult to believe, the US has tons of contingency plans in the event of Congress somehow being largely disabled/made unable to work by way of some external crisis (i.e. a war, especially a nuclear one), 9/11 would not only have to target Congress while it is in session but all of the replacement senators/representatives that state governments could line up in the event of the death or disability of current ones as well. Simply put, it's hard enough to target Congress in session, but if you manage to get rid of that then it is simply replaced, the legislature is incapacitated for a few days at most but in a flurry of last-minute flights and activity they manage to get a temporary Congress in session very quickly, the US expended countless hours and effort planning for this exact eventuality in the event of a nuclear attack on Washington that could potentially cripple the American government in a critical moment, the amount of time it would take for a president to take the amount and scale of the actions (i.e. interning American Muslims or other groups) would simply not be enough, it also wouldn't be the first action any president considered undertaking, while I absolutely believe that the idea of a modern president taking such a drastic action is completely implausible given the circumstances, I'll humor the idea with the condition that its still bound by both logistics and other considerations, simply put, it won't succeed, Congress won't allow it, and neither will public sentiment.
Internment is a bad precedent because it was 60 years ago and most of the internees are dead or getting old enough to the point where the only people who have any sort of direct experience regarding internment are going to be their children, and pretty much all of the people in government who made the decision are dead as well. It really is not too out there to say that the America of the 1940s was simply not the same as the America of the new millennium.
And Wilson's behavior, while certainly not fascist, was very much authoritarian.
While I am not in the mood for a Sedition Act argument because they inevitably devolve into morality circle jerks I think you could make the argument that a good amount of the factors you listed that made turn of the century America ripe for fascism were alleviated by Wilson's presidency. While he was lock step behind certain aspects of it, a lot of matters in regards to economics and class stability were brought to a decent resolution by Wilson's "New Freedom" policies: creating the Federal Reserve, the Federal Trade Commission, limiting child labor and other Gilded Age excesses, etc.
Though the worst of the Red Scare I think really did play out in its effects following the Wilson administration and how America in the 20s largely turned in on itself and its own problems to be isolated from the rest of the world. So fascist America would be more reminiscent of Stalin's Soviet Union in its foreign policy in my view, a lurking, monstrous power with its own ambitions isolated from the world but feared by it just the same.