There are at least a dozen Republicans considering a run for the White House in 2012. As part of a series, NPR is profiling some of them to find out what first sparked their interest in politics.
In the fall of 1976 — the bicentennial — Rick Santorum was a freshman at Penn State University. He didn't know what he wanted to major in, so he signed up for Political Science 1. The course was called "Introduction to American Politics," and that's just what it was for the young Santorum.