That's why he spends the first half of the article quoting nothing but Jewish pundits.
Yes, including Mickey Kaus of Slate, who agrees with Buchanan and disagrees with the other pundits (all of whom are quoted as complaining that criticism of them equates to anti-Semitism, which is a convenient shield for a pundit to have, you must admit).
And Buchanan goes on to criticize all the gentiles I mention, plus writes that America has a moral obligation to Israel. But you wouldn't want to worry about anything that complicates the "Buchanan hates all Jews" thesis, not would you?