> How has Chomsky's strategy worked?

It's worked incredibly well. The United States - the country with easily some of the most well protected free speech laws - continues to be one of the most diverse and welcoming countries in the world. It's one of the most desired places for people to immigrate to, and continues to have a large foreign born population. By comparison, look at how a single digit percentage influx of foreigners rattled Europe. When racists do gather it usually results in plummetting support for their causes. This was the case with the Unite the Right rally: following the rally support for the movement dropped considerably.

By what metric has Chomsky's strategy failed? You seem to be postulating this as fact, without anything backing it up.

"By comparison, look at how a single digit percentage influx of foreigners rattled Europe."

Islam played a role in that. Europe and Islam have been on mostly fighting terms since around 700 AD. There is much smaller cultural difference between the mostly Hispanic immigration into the US and the mainstream American culture than there is between the mostly secular European cultures and people from, say, Afghanistan, who express significant support for things such as Shari'a law.

Thesis is that rational discourse would triumph over lunacy.

Did it?

It's amusing that Chomsky at least says one sensible thing, and that's what causes the far left to reject him.

Chomsky is the far left, at least in America. Of course the neoliberals (center-right) rejected him.

Seems like it's worked well? Wikipedia tells me that he's "one of the most cited scholars alive" and "has influenced a broad array of academic fields"; I'm not personally familiar with his academic work, but most of my friends strongly endorse his perspectives on capitalism and foreign policy. It's hard to see how compromising on free speech could have led his ideas to be more successful.