It wasn't until the final minute of Wednesday night's debate in Indianapolis that conversation turned to one of the hottest topics in Sen. Richard Lugar's (R-Ind.) reelection bid.

"The first thing I'm going to do to represent Hoosiers is to be in touch with them. I'm proud to call this state home," said Lugar's Republican primary challenger, State Treasurer Richard Mourdock, asked about his prospective role as a senator in national and state politics. Before answering, Mourdock clarified that it was the last question of the debate.

"It is a place that if I have the privilege of serving as your U.S. senator, I'm not moving from. I will always call Darmstadt, Indiana, home," he added, comparing the U.S. to the Titanic-soon to face the icebergs of national debt and unsustainable entitlements, and unable to afford a sleepy, negligent crew.

And with that, the debate was over. As the only one scheduled before Indiana's May 8 primary, it was perhaps the only time voters will hear Mourdock make this line of attack in Lugar's presence.

Lugar was not afforded the opportunity to respond, nor was he imposed with the burden of having to.

It could have been uncomfortable for the six-term senator. Lugar has faced criticism recently because, while in office, he sold his Indiana home and took up residence in Washington, D.C., although his Indiana driver's license still bears the old, now inaccurate Hossier State address. Last month, the elections board in the county where Lugar and his wife once lived ruled them ineligible to vote there. Lugar has said he and his wife sold their home in 1977 because moving to Washington, D.C., was the only way to keep their family together and stay active in their son's school life.

Compounding matters, Lugar will repay $4,500 to the U.S. Treasury after he billed taxpayers for hotel stays in Indianapolis for visits to his home state,  Politico reported last month. And he's facing conservative opposition from the National Rifle Association as well as Freedomworks and the Club for Growth, both of which funded Tea-Party challengers against established incumbents in 2010.

Mourdock said at the debate's outset that he is challenging Lugar because members of the Indiana Republican State Committee asked him to. That offer had come as a surprise to Mourdock, given that Lugar has represented Indiana since 1977, is the senior-most Republican in the U.S. Senate (tied with Utah's Orrin Hatch), sits atop the Foreign Relations Committee as its ranking member, and coauthored the most significant nuclear disarmament bill (Nunn-Lugar) of the post-Cold-War era.

Lugar has a reputation as an old-guard Senate moderate, once appearing (in still-frame) in a 2008 campaign ad for President Obama that highlighted the latter's bipartisan nuclear-nonproliferation work in committee. Mourdock, as the challenger with Tea-Party backing, might be written off as a conservative fringe candidate in the 2010 mold of Sharron Angle or Christine O'Donnell.

At Wednesday's debate, however, two even-keeled candidates voiced the standard conservative-Republican stances of the day.

Lugar called Rep. Paul Ryan's (R-Wis.) budget proposal a "remarkable plan … [that] certainly bent the curve back toward the balanced budgets," while touting his votes for Ryan's last controversial budget plan in 2011. He assailed executive-branch regulations on businesses: "You almost have the feeling that folks in those bureaus think it's now or never in terms of trying to control businesses," said Lugar.

Mourdock called for "rolling back the size of government" and, when asked about the economy, called for taking the "jackboot of federal regulations off the necks of small businesses."

Both took aim at "Obamacare" and called for its repeal. Both agreed the Social Security retirement age should be raised. Both said Medicare must be revamped for citizens under the age of 55 and suggested states could better administer Medicaid if supplied with the money in bl0ck grants.

If Mourdock hoped to outmaneuver Lugar by advocating the policies of the GOP's conservative wing, the incumbent matched him at every step.

The challenger respectfully assailed nonproliferation-driven aid for Russia, supported and ushered through the Senate by Lugar, by suggesting that U.S. money is effectively funneling to Iran, via Syria, via Russia.

"The monies that we put into Russia are fungible and can go into parts of the world that are not in our best interest," Mourdock said. "Syria is being propped up in large part … by Russia." Lugar stringently denied this fungibility.

Mourdock made subtle and overt complaints about the current Senate, of which Lugar is such a longstanding part. "The Senate Foreign Relations committee has got to provide more oversight to the Obama adminsitration, should the Obama adminsitration continue," he said of Russian aid. Mourdock said he is more frustrated with Republicans than he is with Democrats, when it comes to government regulations: "I expected this from Democrats," he said. "Congress has not done nearly enough. They will complain about the EPA, but they won't roll it back."

These are the political and policy charges Lugar will have to fend off, although with his residence drawing all the headlines, the race might not be about such agreements or disagreements, anyway.