They both are racist. The only difference is it's not O.K. for conservatives to be racist; a liberal may be given benefit of the doubt and the courtesy media blackout (like the many racist things said by the New Black Panther Party members); a conservative publication knows it will never get that benefit, e.g. on NYT.
Conservatives must be perfect to avoid losing the media blitzkrieg; hence NR fired a columnist who was not perfect. (BTW, Derbyshire has had differences of opinion with other NR writers on, e.g. issues of immigration; I guess his racism hadn't been so flagrant before.)