Will Joe jump ship?

Will the thin reed binding Senator Joseph Lieberman to the Democratic party finally break this week?  For the officially Independent lawmaker, who was Al Gore's running mate in 2000, may be preparing to join the ticket of the presumptive Republican presidential nominee, Senator John McCain.

Lieberman's ties with the Democrats became strained during the aftermath of the US invasion of Iraq in 2003.  Although many of his senate colleagues, including Hillary Clinton, voted with the then-Republican majority in late 2002, authorising President George Bush to use force in Iraq, by 2005 the vast majority of the Democratic caucus had become fierce critics of the war.  But Lieberman stuck to his guns.  As a result, he was defeated in a usually pro-forma party primary in his 2006 re-election bid, but managed to retain his seat by running as an Independent.

Currying favour

Since then, Lieberman has curried favour on both sides of the aisle:

• In the Senate, he has continued to caucus with the Democrats, allowing them to maintain their razor-thin majority.  In return, the party leadership has retained his seniority, giving him a chance to chair the powerful Homeland Security and Governmental Affairs Committee.
• Yet he has also been increasingly inseparable from McCain, who shares Lieberman's dogged commitment to restoring stability in Iraq.  Along with Republican Senator Lindsey Graham of South Carolina, Lieberman was one of the few high profile politicians to stick with McCain after his presidential campaign nearly went bankrupt in late 2007.  He has also accompanied his Arizona colleague on several 'fact finding tours' of Iraq, and backed up McCain's support for Bush's tactically successful 'surge' strategy.

Political separation, or divorce?

Despite his embrace of McCain, Lieberman has largely eschewed direct confrontation with the Democrats -- until now.  In an opinion essay for the Wall Street Journal on May 21, he charged that the Democrats had abandoned the hawkish defence posture of former Presidents Harry Truman and John F. Kennedy, and were now confused about "the difference between America's friends and America's enemies".  He numbered the party's likely presidential nominee, Senator Barack Obama, among these deluded individuals, and accused him of advocating a "blanket policy" of personal engagement, without preconditions, with the most "vicious, anti-American regimes on the planet".

This language may have burned his bridges with the party.  Although many Senate Democrats have privately called for him to be dumped from the caucus, Majority Leader Harry Reid has resisted.  However, with the Democrats poised to pick up several seats in the November general election, his days may be numbered.  Bereft of his chairmanship, his perch in the Senate might lose its charm.

But another shot at the vice-presidency might be some consolation.  McCain is trying to distance himself from president Bush and run as a Republican maverick.  Choosing an ex-Democrat as his running mate, who was on the opposing party's ticket just eight years ago, might help cement that independent image.