Democratic Debate

So I'm watching the debate between Hillary and Barack right now. Why is it that they spend the first 30 minutes talking about individual and personal issues? First they talk about Barack's recent comments in California about "frustrated and bitter" people "clinging to religion and guns." Then they go on about the Reverend Wright situation. Not until 45 minutes into the debate do they start talking substance. And the first two voter video questions were useless. The first was about Hillary not portraying her Bosnia visit accurately and the second about why Barack Obama doesn't at times wear a flag pin. What, if anything, does this have to do with what each of these candidates will do as president?