From Palm Beach to Sderot, wherever Jewish votes can be won, whether by direct appeal or potent symbolism, Joe Lieberman has campaigned alongside John McCain these past months, providing the hechsher to the Republican nominee for president. In this role, Lieberman has traveled a decided distance from his position as Al Gore's running mate in 2000. Back then, firmly within the Democratic Party, Lieberman served as a communal hero for American Jews, a barrier-breaker. This time, as an emigre in all but formal party affiliation to the Republican side, Lieberman embodies the deep divide in the American Jewish vote. You could call him Senator Splinter - both the means and the result of fragmentation. As a steadfast supporter of the Iraq war, and also as a Jew of a certain age and a certain denomination, Lieberman stands Right on the fissures that exist within the Jewish body politic, especially if, as appears likely, McCain faces Barack Obama rather than Hillary Clinton in the November election. All the attention lavished on Obama and the Jews - in the slimy email blasts claiming falsely that he is a Muslim; in the parsing of his team of Middle East advisors; in the innumerable news reports on his controversial pastor, Jeremiah Wright - has left a false impression that he cannot or will not capture widespread Jewish support. The better question might be which Jews. The latest Gallup poll, released on March 24, found Obama trailing Clinton only narrowly among Jewish voters, 48% to 43%. If Jews at large are so traumatized by the Jeremiah Wright affair, which includes the revival of Louis Farrakhan as a campaign factor, then it would not make sense that Obama polls better among Jews than he does among white Catholics or Hispanic Catholics, both of which give Clinton double-digit leads. What is actually going on is not some robotic, monolithic Jewish reflex to reject the Obama candidacy, but rather the fracturing of the Jewish vote into subgroups that lean Left, Right, or center based on a variety of factors. And that is where Lieberman becomes such a fascinating factor. NOTWITHSTANDING THE conspiracy theories of Mearsheimer and Walt, American Jews were deeply split over the Iraq war even at the time of its popular outbreak. Since then, the war has gone through at least two significant phases. First came several years of bloody stalemate with the insurgency, stirring growing disillusionment on the home front. Then, since last summer, there have been the diminished casualties and tenuous stability enabled at least partly by the American troop surge. The surge was McCain's cause from early on, and Lieberman joined him later in endorsing it and essentially taking credit for its achievements. How long the relative calm can last is another matter entirely, as the recent fighting involving US forces, Iraqi government troops and Shi'ite militias makes evident. In a McCain-Obama race, the debate would be over the American endgame in Iraq: staying with what's working versus exiting from what cannot work. To put the matter more Jewishly, the discussion would be which is worse, both for Diaspora Jewry and Israel - a jihadist movement that can use an ongoing Iraq war for recruiting and training, or a jihadist movement that views American withdrawal as victory and proof of weakness. Against that backdrop, it's worth considering how Lieberman's hawkish positions have played out with Jewish voters. In 2000, the Gore-Lieberman ticket carried about 80% of the Jewish vote, according to various exit polls. In 2006, running for his political life as an incumbent in his home state, Lieberman took only two-thirds of the Jewish vote while winning reelection to the Senate in a three-way race. In this year's Democratic primary, Obama won more than 60% of the Jewish vote in Connecticut. So, far from being a unifier for the Jewish vote, Lieberman has come to represent how fractious it is. While I cannot find polling on these exact factors, I also have to wonder how much cleavage has happened along generational and denominational lines, with younger Jews and less-observant or secular ones most drawn to Obama and older, more-religious ones most estranged from him. Lieberman is 66 and Orthodox. While McCain has criticized the Religious Right and been treated with suspicion in return, Lieberman has enjoyed respectful relations, perhaps as a facet of Christian Zionism. While his Judaic social conservatism appeared to draw gentile votes to the Democrats in 2000, it can help move some Jewish ones into the Republican column in 2008, or at least make Obama invest a lot of time and money into holding on to what is normally an assured constituency. (He has already been doing just that in his battle against Clinton for the nomination.) IT DOESN'T take much of a Jewish realignment to make a significant difference, given the high turn-out rate for Jews and their presence in swing states like Florida. When Ronald Reagan won slightly more than 40% of the Jewish vote in 1980 against Jimmy Carter, that shift of traditionally-reliable Democrats was vital to his victory. Although Reagan had a landslide in the electoral college, his share of the popular vote barely exceeded 50%. In nearly every election since then, Republican activists and Jewish conservatives have been waiting for a lasting realignment of the Jewish vote, and time after time, it has not happened. No poll has yet tested how many Jews would switch parties if Obama, rather than Clinton, runs for the Democrats. But a recent Gallup survey indicates that 28% of all Clinton backers say that, in such a situation, they would move to McCain. If the Jewish statistic falls somewhere in the vicinity of 30%, Joe Lieberman might wind up with a title almost as resonant as vice president. And I don't mean Secretary of Defense, his potential slot in a McCain administration. I mean macher.