Or, more precisely, is he willing to abandon the "Democrat" in "Independent Democrat?"
His op-ed in today's Wall Street Journal reads like a prelude to a Dear Nancy letter. Relations have been strained ever since Barack Obama endorsed Ned Lamont over Lieberman when the latter challenged the former in 2006.
After 9/11, Lieberman writes,
"...A debate soon began within the Democratic Party about how to respond to Mr. Bush. I felt strongly that Democrats should embrace the basic framework the president had advanced for the war on terror as our own, because it was our own. But that was not the choice most Democratic leaders made. When total victory did not come quickly in Iraq, the old voices of partisanship and peace at any price saw an opportunity to reassert themselves. By considering centrism to be collaboration with the enemy – not bin Laden, but Mr. Bush – activists have successfully pulled the Democratic Party further to the left than it has been at any point in the last 20 years.
Far too many Democratic leaders have kowtowed to these opinions rather than challenging them. That unfortunately includes Barack Obama, who, contrary to his rhetorical invocations of bipartisan change, has not been willing to stand up to his party's left wing on a single significant national security or international economic issue in this campaign.
In this, Sen. Obama stands in stark contrast to John McCain, who has shown the political courage throughout his career to do what he thinks is right – regardless of its popularity in his party or outside it.
John also understands something else that too many Democrats seem to have become confused about lately – the difference between America's friends and America's enemies.
There are of course times when it makes sense to engage in tough diplomacy with hostile governments. Yet what Mr. Obama has proposed is not selective engagement, but a blanket policy of meeting personally as president, without preconditions, in his first year in office, with the leaders of the most vicious, anti-American regimes on the planet.
Mr. Obama has said that in proposing this, he is following in the footsteps of Reagan and JFK. But Kennedy never met with Castro, and Reagan never met with Khomeini. And can anyone imagine Presidents Kennedy or Reagan sitting down unconditionally with Ahmadinejad or Chavez? I certainly cannot.
If a president ever embraced our worst enemies in this way, he would strengthen them and undermine our most steadfast allies.
Sen. Lieberman has not, to date, served up this degree of criticism. He is dangerously close to abandoning his party's frontrunner, much as Chuck Hagel would be forced to do, it seems, if McCain wins the presidency. Will Lieberman be on John McCain's short list? Hard to say; for every departure from Democratic orthodoxy (he supports tort reform), he's been a passionate advocate for abortion rights, gay rights, and an expansive role for government. In the mind of McCain, Lieberman certainly meets the top two criteria: he could do the job from day one, and McCain trusts him like a brother.