(Credit: Indianapolis Star)

In Indiana, two battles are transpiring. The first is between US Senate candidate Richard Mourdock, a Republican and Representative Joe Donnelly, a Democrat. The second is the ongoing battle between Mourdock and the man he defeated in the primary, US Senator Richard Lugar.

After Mourdock defeated Lugar in the Republican primary on May 8, the Democrats saw an opportunity to gain a Senate seat. Since his first victory in 1976, Lugar never earned less than 54% of the vote and he won with an average of 72% in his last four general elections. By defeating the six-term incumbent and making Indiana an open seat, the Democratic Party saw an opening for a pick-up in the Senate and invested in a race it would have ordinarily ceded to the GOP.

During the primary Mourdock, Indiana's state treasurer, ran as an exuberant right-wing candidate and a likely partisan. In an interview with CNN, he defined compromise as "Democrats joining Republicans." In the general election, Mourdock has tried to cut a path to the center. Now saying "You have to work with people," Mourdock still largely spurns bipartisanship, but added:

"The bipartisanship that has taken us to the brink of bankruptcy has been bad policy. I will work with any Democrat who wants to be pro-growth, who wants to get this country turned around and just make government more effective, more efficient, more accountable."

The Real Clear Politics polling average has consistently shown Mourdock and Donnelly in a virtual tie. The most recent Rasmussen poll has Mourdock ahead by five. The bipartisan Howey-DePauw poll has Donnelly ahead by two. Whatever one might take from these polls, the race is clearly closer than it would have been had Lugar won the primary.

As for the second battle, Mourdock is still struggling against the man he beat in that primary.

Lugar, who pledged he would not openly campaign for Mourdock, conspicuously omitting Mourdock's name, said on the night of his primary loss:

"I congratulate my opponent on his victory in a hard fought race. I want to see a Republican in the White House, and I want to see my friend Mitch McConnell have a Republican majority in the Senate. I hope my opponent prevails in November to contribute to that Republican majority."

Today, the consternation between Mourdock and Lugar stems from a mailer sent by a pro-Mourdock PAC, USA Super PAC, which features a picture of Lugar and reads: "Indiana's Lugar Backs Mourdock in Senate Run. Indiana's Torch Has Been Passed From One Great Leader To Another."

According to Lugar spokesman Andy Fisher, the Republican senator wanted no part of the mailer:

"During the primary, Mourdock and his supporters perpetuated misleading statements about Sen. Lugar . . . Unfortunately, that has continued with this mailer funded by a committee that spent over $100,000 to defeat Sen. Lugar. It was clearly unauthorized and done without consultation with us. Lugar clearly stated on Sept. 17 that he would not campaign for Mourdock in the general election for senator from Indiana."

However one might interpret what Lugar meant on May 8 by "I hope my opponent prevails in November," he clearly did not want to be seen on a mailer that insinuates that he publicly supports Mourdock.

The angst, however, does not stop with Senator Lugar. According to a Howey/DePauw poll, six in ten Lugar primary voters do not support Mourdock in the November election. Libertarian Party candidate Andrew Horning, who has been included in the debates, is also polling as high as 7 percent. So not only is Mourdock having difficulty corralling wayward Lugar supporters, who have a voting outlet that is not the Democratic candidate, but also independents who are not attracted to the zeal of Mourdock's partisanship.

The great irony in Indiana, though, is that Lugar's reputation was one of moderation and as one who worked with Democrats. During his tenure, Lugar voted to confirm President Obama's Supreme Court nominees and authored the Nunn-Lugar program to dismantle nuclear weapons in the former Soviet Union, but he also voted for some of the most excessive government programs:  TARP, the Iraq war, and Medicare Part D.

The reaction to the mailer speaks volumes. It may or may not imply Lugar openly supports Mourdock, but the senator did say on Election Day that he wanted his opponent to win, so extrapolating support for Mourdock was not a great leap. For a senator who was known for geniality, he may be leaving office with a trail of sour grapes for many Hoosier State Republicans.