Complex sentence: In a column in "Salon magazine", where he is regularly published, Horowitz described his opposition to reparations for slavery; he believed that it was racist against blacks, trying to define them only in terms of having descended from slaves.
Split into simpler sentences: In a column in "Salon magazine," where he is regularly published, Horowitz described his opposition to reparations for slavery. He believed that it represented racism against blacks, as it defined them only in terms of having descended from slaves.