The remarks Obama made in his 2003 address to the AFL-CIO (the video) are:

So the challenge is, how do we get federal government to take care of this business? I happen to be a proponent of a single payer health care program. I see no reason why the United States of America the wealthiest country in the history of the world, spending 14% of its Gross National Product on health care cannot provide basic health insurance to everybody. And that’s what Jim is talking about when he says everybody in, nobody out.

A single payer health care plan, a universal health care plan. And that’s what I’d like to see. And as all of you know, we may not get their immediately. Because first we have to take back the White House, we have to take back the Senate, we have to take back the House.

His campaign has put up a response on their site:

Obama Has Consistently Said That If We Were Starting From Scratch, He Would Support A Single Payer System, But Now We Need To Build On The System We Have

As proof that his position has been consistent since 2003, they offer three quotations, one from as early as 2007.

He does make the "from scratch"/"current system" distinction in those quotations, but that doesn't square with his 2003 remarks. And this is a place where the meta of the debate has clearly taken over both camps, where proving that one has been (in)consistent on policy statements is more important than policy itself.

While Hillary's saying that Barack has been inconsistent in his rhetoric on health care, it seems that she's forgotten that a lot of people might find his older position a lot better than her plan. And Obama's response that amounts to "Trust me, I've always been in favor of second-rate health care" assumes throughout it that single-payer is an already agreed upon high-in-the-pie fantasy and that anyone who wants it is a goat.

Sure, he's changed his position, and his response is weak at best. But why doesn't either of them take this opportunity to support single-payer?

Instead, Obama reminds us that while he would love a single-payer system, he doesn't want to do anything that's too "disruptive" to a system that people have "known for most of their lives." I believe someone's left either his audacity or his hope at home.