With the campaigns for the Democratic nomination running so closely, the media and party activists have begun to focus on how some 796 "superdelegates" will cast their votes at the Democratic National Convention in August. The numbers are key. There are 4,049 total delegate votes total. A candidate needs 2,025 to secure the nomination. Of those delegates, superdelegates count for about one-fifth of the votes at the convention.

The latest urban legend about Sen. Hillary Clinton has drawn the attention of fact-checkers everywhere. The presidential candidate, it is alleged, helped defend Black Panthers accused of murder.

Politifact quotes the version of the e-mail it has seen:

The rumors began to circulate in 2006, maybe earlier: "Barack Obama is a Muslim," "Barack Obama is a secret Muslim," "Barack Obama is a Muslim Manchurian Candidate who will impose