By David Nather, CQ Staff

When Barack Obama picked Senate Foreign Relations Chairman Joseph R. Biden Jr. of Delaware as his running mate, he also inherited an entire plan for the future of Iraq.

Now, the two are sending the message that they both support it — but only if the Iraqi people want it.

Biden’s plan, written with Leslie H. Gelb, president emeritus of the Council on Foreign Relations, would turn Iraq into a loose federation of Shiite, Sunni and Kurdish regions with broad autonomy to run their own affairs, leaving the central government in charge of common interests such as border security, foreign affairs and the distribution of oil revenue.

It was a controversial plan, criticized by Iraqi Prime Minister Nouri al-Maliki and even the U.S. Embassy in Baghdad, which posted a statement on its Web site last fall declaring that “attempts to partition or divide Iraq by intimidation, force or other means into three separate states would produce extraordinary suffering and bloodshed.”

But Biden insisted that the critics were wrong and that the plan was about federalizing Iraq, not partitioning it. And the Senate seemed to agree. In September 2007, on a 75-23 vote, it adopted a non-binding “sense of Congress” resolution endorsing the Biden plan — a great talking point for his presidential campaign. “I’m the only one with a clear plan adopted by a majority of the foreign policy establishment, 75 senators,” Biden boasted in November 2007.

Of course, a 75-23 vote means two senators weren’t there to express an opinion. They were, naturally, Obama and Sen. John McCain , R-Ariz. McCain is now criticizing it, but Biden’s team says Obama always supported it — with the crucial qualifier that it can’t be forced on the Iraqis.

“Senator Biden and Senator Obama continue to believe that federalism is a good solution if that’s what the Iraqis decide,” said Biden spokesman David Wade. “That was the resounding bipartisan message the Senate sent last year passing the Biden amendment, which Senator Obama endorsed.”

Sounds like Biden’s speechwriters will have to tread carefully on that one from now through November.