Josh Barro is the scum-sucking dirtbag who got John Derbyshire turfed from National Review. He is a prime example of how ethnic quotas for white Hispanics (aka Conquistador Americans) supercharges the effects of the Peter Principle.
Barro advocated that NR fire Derbyshire because of a piece Derbyshire wrote for Taki's Magazine. Barro said that the firing was necessary if NR wanted to remain credible.
Rich Lowry did fire Derbyshire, but I doubt that Barro forced him to do so. I think Lowry had had enough, and Derbyshire did it to himself.