There's a bunch of support out there that's in the shadows, afraid of the sunlight because the GOPe will see them and if by some measure Trump's not the nominee there will be hell to pay.
That said I too am surprised that Cain hasn't endorsed. He's praised him and encouraged him...just go all the way.
Radio talk hosts run a huge risk of backlash from listeners. Their audience is as split over the candidates as America is. I can understand why they wouldn’t endorse.