HARTFORD -- Looking to rekindle the political fire that had earned him favor among moderate Republicans, Democrats and independents before he became a casualty of President Barack Obama's 2008 coattails, former U.S. Rep. Christopher Shays formally embarked Wednesday on his run for this year's GOP U.S. Senate nomination.

Shays, 66, chose the Old State House in Hartford, an 18th-century landmark a few blocks from where he served in the General Assembly, for a belated campaign kickoff event that drew a mix of Republican leaders and former aides.

Shays had represented the 4th Congressional District for 21 years before losing to Democrat Jim Himes, in large measure because of Obama's strong showing in Bridgeport. On Wednesday, Shays touted himself as an independent-minded public servant willing to put his principles ahead of his party to balance the federal budget, create a national energy policy and build consensus in a town known for partisan gridlock.

Shays served up his message with an ample helping of red meat, ever mindful of the challenge that awaits him in the GOP primary race -- former WWE (World Wrestling Entertainment) Chief Executive Linda McMahon.

"Three years ago, America elected a president with no experience, and we are paying the price," Shays said. "He spoke about hope and change, but he was elected without the skills, experience or background to lead our country through these difficult times."

Shays vowed to repeal the controversial health care law brokered by the president, though he stopped short of calling it "Obamacare," and to introduce legislation to balance the federal budget during the six years of his first term.

Shays alluded to McMahon a number of times in his speech and when taking questions from reporters, telling about 100 supporters that there would be no learning curve should he be elected to fill the seat of retiring incumbent Joe Lieberman.

"We can't afford to send someone to the United States Senate who doesn't have the experience and a proven record of getting things done in Washington," Shays said. "There is no time for on-the-job training."

McMahon shattered the record for self-funded candidates in Connecticut during the 2010 Senate race, won by Democrat Richard Blumenthal by 11 points, when she spent $50 million of her wrestling fortune.

"If you spend $50 million so recklessly why would anyone think that they would spend your money in any other way?" Shays said in a dig at McMahon.

Both McMahon's campaign and the Democratic opposition quickly set out to define Shays as a career politician rooted in the ways of Washington.

"For nearly 20 years, Chris Shays represented the people of Connecticut's 4th District in the United States Congress," said Erin Isaac, a spokeswoman for McMahon. "But in 2012, we need to elect people committed to changing not only the negative political culture, but the ineffective way Washington does business."

The last time Shays was on the political stage was in November 2008, when he delivered a concession speech after being defeated by Himes in a congressional district that covers most of Fairfield County and a sliver of New Haven County.

To add insult to injury, the FBI arrested Shays' longtime campaign manager a few weeks after the election for -- unbeknownst to Shays -- embezzling campaign money for the purchase of electronics equipment, Red Sox tickets, dinners and a hotel room, resulting in prison time for the ex-aide.

Looking to show that his campaign is no slouch when it comes to endorsements, Shays rolled out a number of household names Wednesday in Hartford, headlined by former Lt. Gov. Michael Fedele and Rob Simmons, who served with Shays in Congress and lost to McMahon in a three-way GOP Senate primary in 2010.

The three other Republicans in the race are Hartford lawyer Brian K. Hill, a former U.S. Army Judge Advocate General's Corps officer who lives in Windsor; Peter Lumaj, a Fairfield lawyer who was born in Albania; and Kie Westby, a Southbury lawyer and Republican State Central Committee member.