In Cafe Society because more about TV practices than politics:
UP is a talk show (on right now as I type this) with analyst Chris Hayes and a rotating panel of guests. It seems obvious to me that the guests will interrupt and talk over each other freely, but almost never squeak a peep while Chris Hayes is talking. Now, he’s a brilliant guy, but so are many of them–my question is whether he (or other hosts) actually instructs the panel beforehand not to interrupt him–“It’s my show, and I and only I get to filibuster if I like”–which would be slightly obnoxious but not unthinkable, or if they voluntarily refrain from interrupting him because they want to be invited back and being rude to your host is not a path to popularity with him.
I can’t say it applies in this particular case, but the guests usually know they’ll get their mike cut if they interrupt the host, but not for interrupting the other guests. Some of this is simple practicality, the commercials are typically programmed on these shows and the host has to lead in and out of the ads on schedule.
I’ve only seen the show a couple of times, so I’m just guessing. But could it be that at least some of Chris’ moments are taped separately? They might record the freewheeling discussion, then have Chris add some comments on the way to commercial in the final edit.
Not in this case, at least – I think the show is broadcast live.
I’m inclined to agree with TriPolar, with the caveat that guests who interrupt the host too often tend not to get invited back. For what it’s worth, and I could be mistaken, but I think that the only host who regularly has guests talk over him is Bill Maher.