Probably paid callers.

I've seen several posts here over the years about people trying to get into or make extra money in the voiceover industry being callers on his show.

I've noticed two things:
1. The clarity of the calls - no background noise and no one sounds like they're driving
2. They are remarkably calm and composed for supposed first time callers. My own experience calling local radio tells me that's a red flag. After a few times you get the hang of it but the first few are pretty nerve racking.

can console themselves with the fact that they are unlikely to ever see them in real life.

for a professional meeting and have been thinking about what I want to see and do if I have some spare time. There are some very interesting exhibits at your link....maybe I can go check them out!

Enjoy

is fit to say Obama's name let alone comment on his portrait.

This is no joke, those are horrible people.

and give them a phone call.