According to Hot Air:

This is one of the meatiest segments on the McCain-conservative divide I’ve ever heard. Former Senator Rick Santorum makes point after point after point against the candidacy of John McCain, but also makes several solid points in favor of the Mitt Romney candidacy. Be sure to at least stick around for the middle, when Santorum talks about an encounter with a McCain staffer after losing his Senate seat.

At the end of the segment, Laura Ingraham joins Santorum in endorsing Mitt Romney for president.