In a prelude to the expected battle over the next Supreme Court justice nomination, an historian explains the selection and confirmation process and the past battles between Congress and the president.

Supreme Court Justice Sandra Day O'Connor resigned Friday after 24 years on the bench. Margaret Warner and Jan Crawford Greenburg of the Chicago Tribune talk about O'Connor's role on the Court.

The Supreme Court's term came to an end after the justices ruled on a number of controversial matters, saying local governments can take private property for the purpose of economic development, federal agents may prosecute users of marijuana for medical…