This is a really good story from the Washington Post on Bill Clinton.
I urge you to pay special attention to the tension within the Democratic Party, which has had to grapple with the Clinton/centrist approach to leadership and the Obama/progressive approach. The infighting might not be as pronounced as the conservative and moderate fight within the Republican Party, but I think the Democrats' wounds are covered up because they are in power. Put them in the minority in Congress and out of the White House and watch the sparks fly.
And speaking of tension, Politico.com notes that Bill Clinton being in the news this time is not a good thing for Barack Obama.