By Stuart Rothenberg

As the midterms approach and substantial GOP Senate gains seem inevitable more attention will fall on Connecticuts soon-to-be-senior Senator Joe Lieberman (ID). Thats because Lieberman one of two Independents in the Senate could become a major target of Republicans if they net nine seats in the midterms.
If that were to happen and its still a long shot Lieberman would become either the Democrats 50th vote or the Republicans 51st for organizing the Senate. Either way he could decide which party would control the Senate for the last two years of President Barack Obamas term.
Getting to plus nine" for Republicans doesnt look as impossible as it once did.
Assuming that the GOP holds all of its own seats the party would need to win four Democratic open seats (Delaware North Dakota Illinois and Indiana) and knock off four Democratic incumbents (in Arkansas Nevada Pennsylvania and Colorado). The crucial ninth seat would then come from one of four states: California Connecticut Washington or Wisconsin where Democrats either have potentially vulnerable nominees or Republicans have surprisingly interesting candidates of their own.
Lieberman certainly would relish the attention of being the decider" and his decision surely would take into consideration whether he plans to seek re-election in 2012 when he will be 70 years old.
Shortly after he was first elected in 1988 the Almanac of American Politics wrote that Lieberman is likely to be more of a team player in his party than Republican Lowell Weicker was in his."
I suppose that may be true only because the Connecticut Senator was such a thorn in the GOPs side but in any case it failed to imagine the kind of political figure that Lieberman would become in his own right.
Like Weicker whom he defeated by less than a point for the Senate seat Lieberman last won statewide office in the Nutmeg State as an Independent. But while Weicker won a term as governor running on A Connecticut Party line (a party he founded) Lieberman still operates in a very partisan body and has found himself in the middle of partisan maneuverings.
Though conservatives found Weickers style and voting record impossible to swallow he never faced a primary challenge for renomination since each time he sought re-election a GOP convention selected him to carry the partys banner.
Lieberman of course lost the 2006 Democratic primary to businessman Ned Lamont only to win re-election that November as an Independent with the help of a strong showing from Republican and independent voters.
Even though Democrats rejected Lieberman in 2006 he chose to caucus with his old party after those elections receiving the chairmanship of the Homeland Security and Governmental Affairs Committee (of which he was the ranking member before the 2006 elections).
There are many reasons why Lieberman would vote with Democrats to organize the Senate after the 2010 elections.
Hes been a Democrat his entire life and changing parties doesnt come easy to elected officials who have spent 40 years in politics. He served in the Connecticut state Senate and as the states attorney general as a Democrat was the Democratic nominee for vice president in 2000 and ran for the Democratic presidential nomination in 2004.
On many of the key issues of the day from the environment and abortion to the minimum wage cap-and-trade and the auto industry bailout Lieberman is simply closer to Democrats than to Republicans particularly a GOP of tea party activists pro-lifers and Southerners.
But Lieberman seems to like being able to stick it to Democrats now and then as he did when he said he could not support a public option in the health care bill.
The public option I think was raised in the last year by people who really want to have a government-controlled health insurance system. Thats their right. I think theyre wrong" Lieberman said in November on Face the Nation" using language that must have sounded comfortable to even the most conservative Republican.
And of course Lieberman spoke at the 2008 Republican National Convention and campaigned for his friend Arizona Sen. John McCain (R) in the presidential race.
Actually Liebermans record is filled with instances where he distanced himself from his party or his partys allies in Hollywood for example.
If Republicans have a shot at getting Liebermans vote to organize the Senate it will be because of foreign policy. With the Obama administration increasingly critical of Israel and Iran continuing to take steps to be able to build a nuclear weapon Lieberman may just believe that Republicans better understand what he considers to be the top issue of the day national security.
But would Lieberman really switch the way Arlen Specter (Pa.) Jim Jeffords (Vt.) and Ben Nighthorse Campbell (Colo.) did? Not everyone agrees.
I dont see him joining the Republicans" says Ira Forman executive director of the National Jewish Democratic Council. Hes had chances to do that already and he didnt take them. Its unlikely that he would in the future."
I think he might" counters Matt Brooks executive director of the Republican Jewish Coalition. Joe Lieberman puts principle above politics and if he thought he could make a difference on important issues he certainly would consider it."
Lieberman could still call himself an Independent but decide to caucus with the GOP. That would drive many of his former friends (and all of his liberal enemies) crazy. But he just might like the idea of doing that.