Wherever goes these days, it seems, Joseph I. Lieberman is there.
When McCain needed a quick reminder in Jordan last week on how to characterize Islamic radicals in Iraq receiving aid from Iran, Lieberman was there to whisper into his colleague's ear. A day later in Israel, the Connecticut senator proved equally helpful, stepping in to help McCain clarify the meaning of the Jewish holiday of Purim.
Whether wearing yarmulkes together amid the throngs at Jerusalem's Wailing Wall, meeting reporters outside 10 Downing Street in London or sporting matching suit-and-sweater combos at a snowy New Hampshire town hall meeting, the two have been nearly inseparable since Lieberman endorsed McCain last December.
As McCain hopes to wage a campaign that appeals to an independent-minded electorate exasperated by the Bush administration and the political status quo, Lieberman, a former Democratic vice presidential nominee, has become something of a symbolic character witness meant to testify to the Arizonan's bipartisan approach.
As recently as 2000, the McCain-Lieberman political partnership might have seemed unthinkable. At the time, McCain was running for the Republican presidential nomination. And Lieberman was one of the nation's most prominent Democratic politicians, a well-respected centrist whose selection as Democratic presidential nominee Al Gore's running mate drew widespread praise.
But always more moralistic than some in his party, Lieberman's hawkish tendencies have put him squarely out of step with his party, a fact underscored by his dud of a presidential run in 2004.
His steadfast support of the war in Iraq, while the vast majority of Democrats soured on the conflict, left him increasingly isolated. His 2006 Senate primary election loss to a neophyte challenger underscored his fall from favor. Lieberman ultimately won reelection, but it was as a third-party candidate.
Though he had initially wanted to stay out of the 2008 presidential fray, Lieberman was swayed by a personal appeal from McCain, an aide to the Connecticut senator said. Shortly after returning from a trip to Iraq together over Thanksgiving, McCain asked for his colleague's support, saying it would make the most difference before the New Hampshire primary, where independents and Democrats can participate.
But even after the GOP contest moved to states where his influence was limited, Lieberman wasn't sidelined. The senator whose party affiliation is now "Independent Democrat" appeared with McCain in conservative South Carolina and in some of the most heavily Republican parts of central Florida.
Besides South Carolina Republican Sen. Lindsey Graham, who joined the duo on their overseas trip last week and who enjoys something approaching favorite nephew status with McCain, no other elected official has taken as visible a role or become such a ubiquitous presence in the McCain campaign as the junior senator from Connecticut.
Newly energized and again relevant in national political circles, Lieberman is already being talked about as an obvious pick for a McCain administration, likely as secretary of defense or some other high-profile foreign policy post.
McCain strategists see great value in the dissident Democrat and promise that Lieberman will play a key role in the general election.
"He contradicts the DNC caricature [of McCain]," says Mark Salter, McCain's closest aide and former chief of staff.
As Democrats seek to portray the Arizona senator as representing a third Bush term, argues Salter, Lieberman's willingness to back a Republican "exposes that for the emptiness that it is."
"It's a great story about character and courage," adds Charlie Black, another top McCain dviser, alluding to Lieberman's unlikely path from would-be Democratic vice president to senior surrogate for the GOP standard-bearer.
"And it reinforces McCain's character and courage," he adds, hinting at the Republican's own willingness to buck his own party for principle. "[The endorsement] would not have happened for any other Republican."
Nor would it have happened at all had Lieberman not been so at odds with his former party.
"Clearly that primary challenge he faced was a turning point in Joe Lieberman's political career," says Will Marshall, a co-founder of the once-Lieberman-headed Democratic Leadership Council and director of the Progressive Policy Institute. "That experience liberated him to follow his conscience on other political questions."
Lieberman, who an aide says has only signaled a desire to keep serving in the Senate, has disappointed some of his admirers by coming out for McCain.
"I wish I understood it," laments Steve Rabinowitz, a Democratic strategist who stuck by Lieberman in 2006 even after his primary loss to Ned Lamont. "I just don't know what to make of him anymore. I'm very sad."
Rabinowitz speculates that Lieberman has entered a nothing-left-to-lose phase and that his endorsement strikes the first notes of a political "swan song."
Those close to McCain and Lieberman, however, argue that the endorsement is the natural outgrowth of a long-budding relationship that has been cemented by a shared belief in the primacy of the threat of Islamic extremism.
While the two have served together for nearly 20 years in the clubby upper chamber, it wasn't until the late-90s that they really bonded.
As members of the Senate Armed Services Committee, the pair grew close while traveling together on congressional trips much like the one they took to Europe and the Middle East last week. Their friendship took root as they became regulars at the Wehrkunde conference, a Munich confab held every February that draws military and security experts from around the world.
McCain and Lieberman also joined forces on the two preeminent foreign policy issues of the era: American intervention in the Balkans and the decision to launch air strikes against Iraq.
"The split of the two parties on foreign policy compared to the '90s is crucial to understanding Lieberman," says Bill Kristol, The Weekly Standard editor and a friend of both men. "He hasn't changed his mind."
For his part, on domestic issues, McCain also has moved closer to Lieberman's brand of DLC moderation.
Just as Lieberman is now liberated from following political orthodoxy, McCain went his own way after losing the primary to Bush in 2000. The two paired up to sponsor legislation, opposed by the administration and most Republicans, addressing global warming, and introduced the measure creating the 9/11 Commission over the initial opposition of the White House. They were also key players in the bipartisan Gang of 14.
Those close to Lieberman, however, say that his decision to so enthusiastically get behind McCain is borne in their shared experience as party loners, as much about persona as policy.
"First and foremost, it's character," says Dan Gerstein, a Democratic strategist who helped lead Lieberman's 2006 campaign and previously worked in his Senate office. "This is purely a personal decision and is based on faith and belief in McCain."
Gerstein, asupporter, shares the same concern of other Democrats: that Lieberman could serve as exactly the sort of validator for McCain's independence that the Arizonan's aides are counting on.
Lieberman could be especially helpful in Florida, with its heavy Jewish population, says Gerstein.
But Marshall, the DLC co-founder, suggests that Lieberman could be useful in a more unconventional way - with gentiles.
"Oddly enough, Joe Lieberman may have more credibility with religious voters than the very secular John McCain," Marshall says.
More than anything, though, Lieberman could aid McCain's effort "to run a campaign that transcends the limited reach of the Republican coalition," observes Marshall.
"It feeds the McCain image of being attractive to independents and crossover Democrats," agrees Rabinowitz, who supports. "At best, it's not helpful for us."
The key may be which Lieberman emerges: the affable vice presidential nominee of 2000 or the charisma-deficient presidential candidate four years later.
"My only hope is that he's able to deliver as few people to McCain as he did to himself," Rabinowitz says.
By Jonathan Martin