The answer to your question has been answered today. It is now obvious that the Republican Presidential candidates are afraid of being asked non-scripted questions or questions of substance and will go to great measures to avoid having to attempt to answer those kinds of questions.
Well yeah dude... I could have told you that. Same with democrats.
And we know why. When you allow the public to ask questions on air, without a filter, you get crazy people. It's a fact of life. There are lot of crazy people out there.
I still remember back in the 90s, some Democrat in California, was having an open meeting, and this nut case stood up and said that the reason people had Crack in CA, was because Reagan fired all the air traffic controllers, and without any air traffic controllers, the CIA was guiding Mexican drug lords in by plane, to California, and targeting black communities with crack. I watched the tape, that's what she said.... "so what are you going to do about it?".........
Guess what.... not very many unscripted open meetings anymore. Not so many "questions from the public" anymore. More DNC plants in the crowd, offering soft-ball questions.
What a shock. Republicans don't like that either. No politician likes being asked crazy questions, that paint them into a corner where you either offend everyone on one side, or being accused of supporting the claim because you refused to respond to crazy.
Trump had that happen. Some nut job, spewed a bunch of crazy, and Trump said yeah yeah I'll look into it, and what the left things he supports that crazy, because he didn't bother with responding to the crazy.
Yes, politicians don't like unscripted crazy questions from the public. This is not new. Or special, or anything that anyone should be surprised or concerned about.