First of all a large portion of his crowd is non supporters, you can literally hear the booing over the cheering. Second his supporters seem to be really dumb, and not the I'm sick of it I'm just voting Trump dumb but the I can't spell Caucus wouldn't know how to google when they are, and don't even think they are important dumb. I could easily see him under 15% in Iowa, then good luck convincing his supporters it isn't over, it's not like the Ron Paul crowd who showed up anyways. Another thing to keep in mind supporters of any other candidate who might be busy on caucus day will make a point of showing up to defeat him, if his supporters don't show up at well beyond average #'s he will fall short. Primary states might be a different story, but he could easily lose all the momentum out of Iowa. I also think his crowd might not be as real as it seems, when you aren't airing ads you have a lot of $50 bills lying around, and the reality is his rallies are not being held in the biggest buildings in the world, these are minor league hockey rinks and college arenas I bet you couldn't fit 8,000 people in most of these places, and that's before you make the stage way bigger then it needs to be, open up a few rows for security purposes and make sure to allow as many protesters as possible in. It wouldn't take many paid seat fillers to create the appearance of a can't miss event. Think of how he built his business, it wasn't about actually making money it was about the appearance of making money. Now that Limbaugh Glen Beck and others have turned on him it's all over.