>>the others running, except for Chris Christie, seem deadly afraid of him

My hat's off to Christie. As best as I can tell, he's running so he can deflate Trump, not for president. On the other hand, Ramaswamy seems to be running for the VP slot. Trump might pick him. He defended Trump at the first debate, and seems to not to have Trump's eventual issue with Pence - being "too honest".

>>his core followers believe that showing up with a sign supporting Trump will land them in prison.

It might just be they don't trust that they can protest without stepping over the line. As it is, I'd consider some of their past non-penalized behavior to qualify as 'menacing' - and law enforcement gave them a 'pass'. This time, they might march right up to that line - and find their wrists in zip ties. All down to the discretion of the local LEOs (who now maybe are getting pressure to be a little less passive with these folks).