I'm inclined to agree with the last post's commenters that the MLK/Obama cartoon didn't quite work. I was trying to convey my excitement that, while we've had a dream since Dr. King's day, there is finally a realistic road map to the White House. Obama's blank expression threw it off.
As I worked on the cartoon, I found that a smile on Obama's face made him appear to be gloating. A stern expression made him appear to be confrontational, which I don't find him to be. So I tried for a look of steady conviction, and didn't quite capture it. You wouldn't believe how much whiteout is on that cartoon.
Live and learn. (Although I'm still not sure how I'd draw it better today.)