McCain denies he said he wasn't an expert on the economy - when he did.
You know, I don't mind a candidate who admits "I'm weak on X issue." Nobody expects even the President to be an expert on everything.
After all, that's what you have advisers for. What we elect a President to do is have the wisdom to know - even in general enough terms - what the right and wrong thing are. Lowering taxes during a war? Bad. Raising taxes on essential needs? Bad. Spending money infrastructure? Good!
So with this good general knowledge, a President can work with experts in the field, know when they are being lied to and when they're being told the right things. They can look at history, and even if we don't expect them to memorize the last P/E rations of the top 5 companies, they have to at least know what is important to spend money on or not.
So I don't mind that McCain says "I'm not an expert on economics." I don't expect Obama to claim to be an expert on military tactics.
But I do get annoyed when someone tries to claim to be everything, or denies that they ever said they were weak on something. McCain's blunder here is the "Oh, I didn't say I was bad at that", when he did. We all admit it - and it would be OK if he just cowboyed up to that and said "But I have advisers A, B, and C that *do* know a lot, and here's why you can trust them - and why I do."
Of course, having Black and Graham as economic policy advisers, especially after Graham's financial screw ups have now lead to the energy and housing credit crisis doesn't inspire confidence. But neither does McCain claiming he's not an expert, then claiming he never said he wasn't, either.