Hmm, the joke doesn’t work as well reversed.
> The most famous anti-fascists were and are communists
You are equating Anti-fascists to communists, which is ... a position.
The most famous anti-fascists are the democrats. Not the American Democrat party - anyone who believes in the ideals of democracy, personal freedom, and equality.
They might be the most numerous ones, but the anti-fascism has pretty much always been claimed by the communists, they even built a famous anti-fascist protection wall to stop the fascists from sabotaging their economy. Very few democrats felt the need to talk about themselves as anti-fascists, that's a far-left thing. Democratically minded people act anti-fascist but don't speak of it. Communists speak of anti-fascism while they torture political opponents to death.
Democracies usually don't call themselves The Democratic Republic Of X. Communist dictatorships do that. Democracies don't build a border wall and call it an anti-fascist protection-wall, communist dictatorships do that.
When someone loudly and repeatedly exclaims how holy and pure they are, my alarms are going off. Yours aren't?
Even if I did: there has never been an “anti-fascist republic of whatever”.
Like all sane people I oppose fascism, but I don't put "anti-fascist" in my Twitter bio, wear antifa t-shirts, or run around loudly telling everybody about how much I hate fascists, because why should I need to? Of course I'm an anti-fascist, who the hell isn't? It feels as unnecessary as having to tell people that I'm "anti-genocide" or "anti-pedophilia".
It's also true that communist regimes have always used "anti-fascism" as an excuse for their atrocities, just like fascist regimes have used "anti-communism" to justify their atrocities. The original Antifa was an offshoot of the German Communist Party, and (as GP pointed out) the Berlin Wall was officially called the "Anti-Fascist Protection Rampart". That doesn't mean that all anti-fascists are communists, but history is what it is.
Don't take any of this as my denying that there are still fascistic forces in our world that should be opposed. If "anti-fascism" is an important part of your identity and you feel the need to tell the world about it, good for you, I'm not going to stop you, but personally I don't see the point.