  Recent measurements of the galaxy clustering environments around
intermediate-redshift radio sources have suggested a systematic environmental
difference between radio galaxies and radio-loud quasars, in contradiction to
the predictions of simple unified models for the two classes of object. I show
that the apparent difference arises mainly as a result of the properties of
low-excitation radio galaxies included in the radio-galaxy sample, which tend
to lie in significantly richer environments. The environmental properties of
high-excitation radio galaxies and quasars are statistically consistent in the
redshift range 0.15 < z <0.4, as unified models would predict.
