It's politics 101. When your campaign has a distraction get rid of him or her. Jim Johnson, welcome to politics 101.
Johnson led Obama's VP search committee but left Wednesday. Read more on that here:
Obama had to cut ties even if he didn't really want to. Any sort of appearance of special interest ties - no matter how inconsequential they may be - leaves a candidate like Obama with no choice. It gave the McCain camp an opportunity to hit him on judgement and hypocrisy since Obama rails against special interests. The media deemed the story worthy and when that happens then "That's all Folks."
Jeremiah Wright. Distraction. Gone. Jim Johnson. Distraction. Gone. There are a few more on Obama's side and some on the McCain side too. The candidate with the least amount of distractions will have an advantage.