(Patrick Raycraft / Hartford Courant)

Joe Lieberman, Connecticut's Democrat-turned-Independent US Senator, is retiring at the end of his term. After 23 years serving Connecticut in the US Senate, Lieberman's seat is finally opening up and the mainstream parties are pouncing at the opportunity to fill it.

Running to claim the open seat are Democratic congressman Chris Murphy and Republican businesswoman Linda McMahon. Murphy has represented the 5th Congressional District since winning in the 2006 Democratic wave. McMahon, the former business manager and president of World Wrestling Entertainment, ran for the US Senate in 2010, losing to Democratic Attorney General Richard Blumenthal.

A Potential Gain For The GOP

Although officially an independent, Lieberman continued caucusing with the Democrats, so a McMahon win would represent a gain for the Republicans and bring the GOP a step closer to regaining the majority in the Senate. As a result, the Democratic Party has poured many financial resources into retaining the seat. The Democratic National Senatorial Campaign Committee has invested almost $900,000, and MoveOn.org has also fundraised for Murphy.

McMahon, wealthy from the WWE, has largely self-funded her senatorial campaigns.

Murphy has touted his blue collar background with a particular emphasis on saving the middle class, Social Security, and Medicare. Speaking to the Yale College Democrats in January, Murphy wondered:

"Whether we are on some trajectory where we're gonna end up with 5% haves and 95% have-nots. . . . There is no mystery as to what happens if the Republicans get control of the White House and they get control of the US Senate. Medicare as you know it is gone. Social Security is handed over to the Wall Street money managers." 

Gridlocked In An Aggressive Ad Battle

In a new campaign ad, Murphy continues the theme by saying, "Linda McMahon's tax plan gives her a $7 million tax cut and it cuts programs for Connecticut's middle class and Medicare for seniors."

McMahon's ads against Murphy are centered on the Congressman's missed mortgage and rent payments. The ads also speculate on whether Murphy was the beneficiary of a "sweetheart" loan from a bank that received TARP funds in 2008 while Murphy was on the brink of foreclosure. The day after the Connecticut primary on August 14, McMahon launched a "robocall" accusing Murphy of voting to cut Medicare by $700 billion, a reference to Murphy's vote for the Affordable Care Act in 2010.

In a recently released video of McMahon at a Tea Party forum several months ago, McMahon opened herself up to further charges of gutting entitlements when she said of Social Security's inception:

"We didn't go back and review it . . . In other words, I believe in sunset provisions when we pass this kind of legislation, so that you take a look at it 10, 15 years down the road to make sure it's still going to fund itself."

While she courted Tea Party support in 2010, McMahon is positioning herself as more of a mainstream, albeit northeastern Republican. McMahon has politely supported the choice of Paul Ryan for vice president, despite not openly endorsing his controversial budget plan.

A Numbers Game

The Real Clear Politics average shows that McMahon peaked in early September and even took a brief lead over Murphy, but most other polls show the lead alternating between the two, a sign that the race is neck-and-neck and could be decided by moderates and independents.

According to a new Public Policy poll, Murphy's support has remained constant at 48% while McMahon's has dipped from 44% to 42%.

As the national GOP sees Connecticut as a possible pick-up, McMahon has received support from 2008 Republican presidential nominee John McCain. In an appearance in Connecticut, McCain praised McMahon for her knowledge about "the economy, and growth, and jobs."

McMahon and Murphy have only one month left to make their cases to the voters of Connecticut. In a state with a history of electing and supporting independents, it may simply be a matter of which major party politician promises to change the least.