Riginslinger commented:

All of that having been said, it seems to me that most politicians put down hecklers as quickly as he/she can.

These shouts of "Kill Him!", though, are not heckling; they're against the opposition, not the speaker. And if the speaker doesn't publicly disown them, then and there, the impression, at least, is that the speaker doesn't object to them or even endorses them.

Dave Oesterreich