As I have noted, denying racism has an evidence problem. But those who persist in denying the impact of poverty also have an evidence problem; thus, they have to manufacture evidence.
But manufacture evidence they will—as evidenced by Hanushek, Peterson and Woessmann (2014). However, David Berliner and Stephen Krashen have now unmasked that effort:
David Berliner Responds to Economists Who Discount Role of Child Poverty
Do American Rich Kids do Worse on International Tests than Rich Kids from Other Countries?
I also recommend this, related: