I think the key difference Gaborn is effect of actions vs. influence on actions.
Bristol's life is affected by the effects of Sarah Palin's actions. In other words, she is a direct result of what her mother has taught and done. A child's actions speak some things about who that parent is directly.
Jeremiah Wright is an example of influence. The question here is whether what he has taught will or has influenced Obama's actions. This can call into question a candidate's judgment, and also whether or not he really believes those things. It is not, however, a 'proof.'
I think the argument can be made that both are more important. However, I think this is stupid bullshit meant to distract from the issues. None of them have a role in how these people will run the country