INDIANAPOLIS (AP) — Richard Mourdock became one of the tea party’s biggest winners of the 2012 primary season when he knocked off veteran Indiana Sen. Richard Lugar in a brutal campaign built on his contention that Lugar was too old, too out of touch and too friendly with Democrats — a RINO, Republican in name only.

But the movement’s biggest RINO hunter is now changing his tune as he tries to woo moderate voters in a tight race that stands as a key test of the tea party’s ability to win outside the nation’s most conservative states.

Mourdock is matched in the general election against moderate Democratic Rep. Joe Donnelly, who is running even in recent polls despite Indiana’s Republican tilt. Suddenly, gone is the strident rhetoric in which Mourdock proclaimed that bipartisanship meant Democrats coming over to Republicans’ thinking and that winning meant he would “inflict my opinion on someone else.” In its place are support for parts of President Barack Obama’s health care overhaul, pledges to protect Democratic-championed programs like Social Security and Medicare, and even the once-shunned notion of compromise.

Welcome to “Extreme Makeover: Mourdock Edition.”

Mourdock’s awkward stagger to the center may be a necessary move if the Republicans are to hold a seat that had been a safe bet since Lugar first won it in 1976. The outcome will help determine whether the GOP manages to win control of the Senate, where Democrats now have a narrow four-seat advantage.

Advertising spending from both sides has topped $6 million so far and promises to explode in the final weeks. The candidates and outside groups have already surpassed the $5.6 million spent in Indiana’s 2010 Senate battle.

The tea party has won Senate seats in South Carolina, Utah, Kentucky and Florida, but only one so far — in Wisconsin — in the more politically diverse Midwest. Mourdock and Texas Republican Ted Cruz represent the ultraconservative movement’s best chance for increasing its clout in this election.

Rather than rally true believers, Mourdock is working now to tie himself closely to the state’s popular governor, Mitch Daniels, who is a conventional business-executive Republican rather than a party insurgent, while tying Donnelly to Obama, who is expected to lose Indiana in November.

But the image change is a stretch for the 60-year-old former coal company executive, known for his fascination with motorcycles and race cars and for his sarcastic criticism of Republicans he considers not conservative enough.

Mourdock, who ran unsuccessfully for Congress three times before becoming state treasurer, won tea party acclaim for an outspoken role in the fight against the auto bailout, for his criticism of Republicans who voted for Obama’s Supreme Court appointments and for calling Lugar’s relationship with Obama a “bromance.” While reliably conservative, Lugar sought common ground with Democrats on foreign policy issues, a stance Mourdock exploited in the primary.

Mourdock now argues he was never just a “tea partyer,” but rather a regular Republican with conservative values.

“I’ve had a traditional base of Republicans out there,” Mourdock insisted in an interview. “Are we going to have all those Lugar Republicans coming over? Some have been slower to join us. But, you know, we’re getting there.”

Indiana’s shift to the right in recent years would seem to benefit Mourdock. The state has defunded Planned Parenthood, approved a right-to-work law that bars employers from requiring union membership and created one of the nation’s broadest school voucher programs.

But Indiana voters have a penchant for split tickets and many are more accustomed to the buttoned-down Midwestern style of Republicanism evinced by the reserved Lugar, the former mayor of Indianapolis, and Daniels, a former corporate executive, than that of the brash Mourdock.

Polls indicate many voters were offended by Mourdock’s slashing attacks on Lugar, even those who thought it was time for the 80-year-old senator to retire. In a statement, Lugar fed those doubts by saying Mourdock’s hard-line approach is “not conducive to problem solving” and would be a ticket to failure as a lawmaker.

When the general election campaign revved up last month, a new Mourdock emerged with a milder message, bonding himself to Daniels and to well-known Republican surrogates such as Lt. Gov. Becky Skillman and Oklahoma Sen. Tom Coburn.

The transformation has left some Republicans shaking their heads.

“The night of the election he was singing the tea party’s praises — ‘I couldn’t have gotten elected without the tea party!’ — and then the clock turned midnight and he’s a mainstream Republican,” said Mike Murphy, an Indiana Republican strategist and former state representative.

Lugar supporter Anne Emison Wishard said Mourdock’s change seems mostly cosmetic.

“I smell panic,” said Wishard.

But Joe McKinney, a 59-year-old education professor at Ball State University who voted for Lugar, said the mainstream endorsements have made a favorable impression. They are “more moderate Republicans who seem interested in the issues I’m interested in,” he said.

Donnelly says Mourdock’s recent appearance at a tea party event in Texas with commentator Glenn Beck showed his true stripes and undercut his “ability to come back and talk to Hoosiers in the middle.” Several prominent Lugar supporters have raised money or hosted meetings for Donnelly.

But Monica Boyer, co-founder of the tea party umbrella group Hoosiers for a Conservative Senate, said Mourdock’s different messages don’t worry her.

As for Donnelly, she said, “He could campaign with Mother Teresa and he would still have ‘Obamacare’ stamped on his forehead."

Posted 9/27/2012