There is no point in it. And it WILL be made to look like an attack. You want to go after Obama with tough questions, the you ask him those questions. There is NOTHING to ask the first lady that can be covered by tough questions.
It is just not done. And rightly so.
Double Tap,
You sound like a defeatist. If the first lady has made contoverial statements in the past, then any good interviewer can at least ask a question about it. Thus the “Oprah Huckabee” label.