Indiana Sen. Richard Lugar is the longest-tenured Republican in the U.S. Senate. In most years, winning a seventh term would be pretty routine and winning his own party’s nomination would certainly be a slam dunk. But Lugar is working hard to fend off a primary challenge from Indiana State Treasurer Richard Mourdock. Mr. Mourdock tells us why he’s running to unseat a member of his own party. He also tells us why he believes Lugar is not even eligible to represent Indiana in Congress. Mourdock chronicles the issues on which he feels Lugar has recently changed his views in order to win the primary. He also responds to allegations he has often been AWOL as state treasurer and that he may be too conservative to win a general election. Listen here for our conversation with Richard Mourdock.