Pay particular attention to the area in yellow. If you compare by week you will see McCain closing in and Obama weakening. Why is this particular poll important? They were the CLOSEST in predicting last presidential election.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .