oh, yeah.....lots of milling and conversing. lots of candidate shirts, buttons, etc.
that is the point of the caucus. there are volunteer speakers for each candidate, if they want to speak...allowed two minutes to lay out the case for their candidate. these “speakers” are not necessarily campaign workers, although they could be. some were just voters that stood up.
interestingly, in my caucus, there were no speakers for trump. not sure why, just stating a fact.
So, then, no public announcement had to be made. Find a Carson supporter and just tell them privately. Sounds pretty easy to do to me.
However, I do value your description of the caucus. We don’t do that here in Ohio. Part of me wishes we did.