Why the Sudden Vilification of Cesar Chavez?

I don't know whether these accusations are justified or unjustified. I have no idea whatsoever.

And I don't know whether this is the right explanation. Again, I have no idea.

However, even if the accusations are plausible/weighty/justifiable, we'd still need an explanation of why they're coming to light / being pushed now--thirty some-odd years after his death.

And I formed the same hypothesis: Chavez was against illegal immigration...and that is now quite politically incorrect.

Just about the last thing the left wants now is for a leftist champion of farm workers being on record against illegal aliens.

Though it should go without saying that hypotheses are cheap, and one of our most common errors in reasoning is to mistake abductive conclusions for inductive ones.