Given his previous description of diversity advocates as those who use sheer force, the only identified locus of intimidation is the PCer. Given his previous description of PCers as those who are on a "crusade," the only identifiable political extremist is the PCer.
Bush coopts the terminological ground through ambiguous uses of "diversity" and "prejudice" and through the comparison of the tactics of PCers to the actions of racists; these rhetorical moves, in turn, allow him to turn PCers into bullies who use intimidation instead of ideas.
He then is able to cast PCers as opponents of freedom because they seek to alter a system that already provides freedom and equality.
For example, Bush's speech seems to establish a faulty comparison between PCers and racists, premised on the delimiting of PC as the exclusive advocacy of speech codes.