I saw this item on Matt Welch's blog 
The audience of about 100 people is all white.
There's much more of interest in his reporting, but that bit stuck out.
Really? What stuck when I read the thing was this:
David Horowitz doesn't mind tackling the controversial (with the elites only, regular folks are dead-set against illegal immigration).
Heather talked about the taboo we have now about illegal immigration's effect on crime. "Reporters just don't bother to ask," she said. "In all the of the [Jose Raul] Pena stories, [Pena's 19-month-old daughter was accidentally shot by the LAPD after he used her as a shield in a violent standoff] the L.A. Times has mentioned once that Pena was here illegally. The New York Times hasn't deigned to mention it a single time."
and Mark Krikorian:
"Any system that a Mexican busboy can slip through is one that an Al Qaeda terrorist can slip through."
However, returning to what originally struck Matt Welch, the putatively all white audience, (Cathy Seipp estimated 95%) I'd guess that David Horowitz sent out invitations without regard to race, creed, or color, and the white people were who showed up.