Antifa is the narrative being pushed by Right wing organisations. In reality it only really exists as a colloquial term for anyone who is anti-fascist. Yes, anti-fascists are rioting and burning, but the notion that it has been orchestrated by Antifa is bollocks.
The right wing, and Trump followers, are defined by their deference and loyalty towards an authoritarian figure. They don't care about values, or political positions or ideologies, which is why all these "good christians" have no problem with the fact Trump had affairs, paid for sex, paid for abortions, lies multiple times a day, is openly misogynistic, explicitly says he doesn't like poor people, and hasn't opened a bible in 50 years.
All that matters is that the authoritarian figure head did it, so it's ok. It's what makes pointing out the hypocrisy and lies and cognotive dissonance so annoying, because you can show them 2+2 = 4, but if Trump says it's 5 then it's 5, and if he says it's 3 tomorrow, it's 3.
Because of that mindset they find it very hard to go up against ideas. It's hard for them to comprehend that tens of millions of people have just decided enough is enough, so they need to find a bogeyman, a group or figurehead to direct their hate and blame.
That's what antifa is. It doesn't actually exist, it's not an organisation or structured group, but Trump can just shout Antifa, and his followers have their single point of blame. Job done, no need to ask why so many of their fellow Americans are protesting, it's all just Antifa's fault.