What was shouted by a supporter?  More importantly, what issue was so offensive that he had to shout it down - what did the moderator of the debate ask about?

bullsh** because the moderator said that they would focus on issues that the candidates could address while in Congress instead of a question Fimian's supporter had submitted about negative campaigning.

I explain the reason for posting the video a little more in depth in the comment section over at Left of the Hill.

Fimian's GOP supporter was none other than Jerry O'Dell. Jerry lives in the City of Fairfax, manages to attempt to disrupt every City Council Meeting and actually, once brought graphics of an abortion to a City Council Meeting. He is against the fact that the City's health plan is with Kaiser. Every election, he runs for both school board and city county..
Kindly stated, Jerry could use some help. Almost feel sorry for Fimian having him as a supporter!

because he did not have the courtesy either to rebuke his supporter or answer the question posed by the interviewer. Sure, Fimian ("Fimian's Rainbow"?) looks like a good, solid, clean-cut, country club white man-citizen, pillar of the community, but he is every bit as much a slig under a rock as the other Republican candidates we are blessed with this year. It almost makes me feel sorry I ever was a Republican, and very glad I am no longer.