At the debate, a gay soldier called up, identified himself as a gay soldier, and asked if the candidates would re-institute DADT. That is when some in the audience booed.
They booed him for asking a question suggesting the GOP should support DADT. There was no reason for ANY of the candidates to "defend the soldier".
Of course, this is only happening to Cain because he is now the front-runner. We saw what they did to Perry, who had been extensively vetted in multiple governor campaigns. Just imagine how they can tear down a guy who has never been through a campaign before.
Unless you are a democrat, I think it's hard make a presidential run if you haven't been through a few gruelling election cycles.
mark