The conservative base’s least favorite Republican senator is arguably Sen. Dick Lugar (R-Ind.). The Maine senators are as conservative as the state will tolerate, many grudgingly accept. Sen. Scott Brown (R-Mass.) does the best he can hailing from the bluest state. But Lugar has irked the conservative base in a generally red state on everything from START to judges. And now Indiana Republicans have a chance to dump him.

Richard Mourdock is businessman who won the race for treasurer in 2006, a tough year for Republicans, and let the GOP ticket with more than 60 percent of the vote in 2010. He navigated the state through the financial crash and drew the attention of conservatives when he filed suit to try to block the auto bailout.

In a long telephone interview, Mourdock tells me that Lugar is n longer in sync with Hoosier voters. “Everyone is concerned about our financial status,” he says. “But in the lame duck session he wouldn’t even vote for earmark reform.” Mourdock says that while it might have been a symbolic vote, even then-Sen. Evan Bayh (D-Ind.) managed to vote for it.

Mourdock is a rock-ribbed Republican who lists Sens. Jim DeMint (R-S.C.), Pat Toomey (R-Pa.) and Mike Lee (R-Utah) among those with whom he identifies. He cites Rep. Michele Bachmann (R-Minn.) for the proposition that what Republicans need is “quality, not quantity.” They could use both actually, and the opportunity to replace Lugar with Mourdock, who stands a good chance to win in a state the Obama camp has reportedly written off, has conservatives excited.

A large part of Lugar’s problem, according to Mourdock, is that he is largely absent and out of touch with the people back home. He recalls that on the day he announced, three-quarters of the GOP country chairman signed on to support him. “The most frequent comment I heard,” he says, “was ‘I haven’t seem [Lugar]in years.’”

In fact, the Evansville local paper ran a column this month that began this way: “When U.S. Sen. Richard Lugar visited Evansville about two years ago, I recall asking folks about the last time Indiana’s senior senator came to town. No one I talked to could remember. If you ask me, that, more than anything else, explains why Lugar is being challenged in the 2012 GOP primary by state treasurer and former Vanderburgh County Commissioner Richard Mourdock.”

Mourdock ticks off a list of issues on which Lugar has upset core conservatives: the DREAM Act, the car bailout (the government “shouldn’t be picking winners and losers”), the START Treaty (“if it was such a good deal why not give new members a chance to review it”), and judges (“he claims he’s conservative yet he voted in reverse order for Kagan, Sotomayor and Ruth Bader Ginsburg”). On the $61 billion spending cut for fiscal 2011, Mourdock recalls he was driving on the roads of Indiana campaigning when he heard Lugar was going to vote against it. “Fifteen minutes later he was going to vote for it.” Mourdock is amazed that Lugar could have objected to a measure by which “we’d have a balanced budget 15 days of the year” and be running up the debt on the other 350.

On foreign policy, Mourdock joins those conservatives who insist Obama hasn’t identified a vital national security interest in Libya. But Mourdock is no isolationist. He supports Arizona Republican Sen. Jon Kyl’s efforts to impose sanctions on Iran, Syria and North Korea. In contrast to Lugar, whom Mourdock says “supports multi-lateralism,” Mourdock argues that there are times when the United States needs to act unilaterally. On Israel, he recalls that after Obama’s Arab Spring speech, in which his language on ”1967 borders with land swaps” stirred up a frenzied reaction, “Lugar said he wasn’t going to take on the president. Well, I would!”

Mourdock argues that his private sector background (he’s a geologist with 30 years in the energy industry) gives him the opposite perspective of many pols, who want nothing more than to be elected. “I didn’t grow up in politics. It’s okay if I don’t win, and I’ll be able to make tough decisions.”

On economics he characterizes himself as a “pro-growth Republican.” He says, “The next 90 days will determine our course.” He cites the debt ceiling vote, the end of “QE2, cold turkey” (he asks, “Who’s going to buy our bonds?”), inflation concerns and Fitch’s downgrading of some major financial institutions’ risk ratings.

Mourdock speaks precisely but with out much flair. He readily admits he is “charisma challenged.” But he’s proven to be an effective campaigner and Tea Party favorite. The largest Tea Party group in the state will almost certainly endorse him in September. He says, “If not for the Tea Party, the Republican Party would not be coming back to its roots” as a party of limited government and lower taxes.

Mourdock is plainly much more in tune than Lugar with the staunch fiscal conservatism advocated by Tea Partyers. Lugar will be 80 years old in 2012, not ancient by Senate standards. Nevertheless, his mushy moderation and Washington aloofness are as out of fashion as hoop skirts. If Mourdock runs a solid race and continues to point out Lugar’s endemic squishiness on issues the base holds dear, he’ll boot Lugar from the Senate, a move that would be almost as popular with the conservative base as the political demise of Sen. Arlen Specter (D/R/D-Pa.).