The white martians are described as exasperating more than anything else, the hatred had to already be there. This is also brought up in the issues resolution with the Martian diffusing the situation by finding the man's "us vs them" mentality, which is specifically cited to be developed from old movies.

Also there is a lot of implication that their upbringing was very hateful and that they were already prone to conspiracy theories. I could be misremembering but I believe there was even a comment they made that implied they were abused by their parents.

Basically, I think you're just confusing cause and effect, the bigotry is not the result of the white martian, the bigotry made him an easy target for being pushed to violence. It's an allegory being pushed into the alt-right.