We remarked on round I here; in round II, Professor Smith calls out Mr. Horowitz on a series of lies and fabrications about events at Bloomsburg University, where Professor Smith teaches.  Professor Smith’s conclusion is apt:

Horowitz would be more help to conservatives by either learning to tell
the truth or shutting up. I have no doubts that conservatives are just
as embarrassed as are centrists and liberals by his fabrications,
misrepresentations and generally outrageous behavior.  He only serves
to scare sober minds away from the conservative movement.  As we have
seen in Horowitz’s tirade against everyone on the Select Committee who boldly stood their ground,
and who rejected his rhetoric and falsehoods, including those
Republicans on the committee who voted to remove the Horowitz-Armstrong
manifesto (the report’s Summary), all who disagree with him are
enemies–including the very conservatives he claims to represent. I
think that it’s time for whoever pulls his purse-strings to give the
man a well-earned "time out."