Sunflowers if you think that the party conference speeches are designed purely for the people in the main hall you're either naive or deluded. The fact we're discussing it on here might be a clue, as is the fact it's one of the top stories on most news outlets as were Milliband and Clegg's speeches.
Party conference speeches are an opportunity for the parties to set out to the wider pubic the parties agenda and to win votes whilst the speech itself is given a decent reception before a sympathetic audience. The speeches certainly aren't designed purely to appeal to just to the delegates when they know it will be reported to a much higher audience.
I don't have a problem with him discussing Ivan (or his father's disabilities) in the right context but when it's done in a speech which is vital for winning support for the Tories it makes me feel incredibly uncomfortable.
And I say this as someone who tends to support the Tories, I just don't like it, it's crass and exploitative.