Dave Davies

It's been 50 years since President John F. Kennedy was assassinated, and polls show that a majority of Americans still believe Kennedy was the victim of a conspiracy, not a lone assassin. Philip Shenon, author of A Cruel and Shocking Act, explores what keeps these conspiracy theories alive.

Wall Street Journal reporters Reed Albergotti and Vanessa O'Connell say that champion cyclist Lance Armstrong was at the center of "the greatest sports conspiracy ever." Their book chronicles everything from group blood transfusions on the team bus to extensive efforts to silence and intimidate those who might expose the abuse.

The president alone can approve or reject construction of the Keystone XL pipeline, which is designed to take crude oil extracted from Alberta, Canada, through America's heartland to refineries on the Gulf Coast. New Yorker journalist Ryan Lizza says Obama could use the decision as a "symbolic turning point in the kind of energy future he wants America to have."