Mike, I agree that Obama's deluding himself if he doesn't expect his patriotism to be questioned if he's the nominee. (Though I strongly doubt he doesn't.) But I thought he did a nice job responding to that question--it's actually his standard response--by emphasizing how he of all people has to love this country because there's no other place where his personal story would be possible.
It brings to mind the spontaneous U-S-A! chants at some of his early victory speeches. (Man those seem like a long time ago, don't they?)