With the "Dean is unelectable" meme seeming to take hold again, as even nominally Dem-leaning mediots attack on everything from the Doctor's irreligiosity (Franklin Foer) to his insufficient genuflecting at Saddam's capture (James Carville), he needs to go back on the offensive and make the argument for why he's a better choice than the traditional Democrats who are starting to gain ground on him. I think the way he should do this is by announcing his support for a balanced budget amendment--and challenging Congress to start balancing the books even before it's passed.
Fiscal discipline is the one area where even conservatives (as opposed to "right-wingers," intellectually dishonest power fiends like DeLay) have to concede that Dean is a stronger candidate than Bush. He has a good story to tell in Vermont, having balanced budgets there to the point where the state fared better in the recent recession than pretty much any other, avoiding big service cuts. And he's already said that a balanced budget is a prerequisite for social justice.
And unlike most of "our" issues, this one is easily reducible to a soundbite: your family has to balance its books and spend responsibly, shouldn't your government?
Politically this makes great sense for almost any Democratic candidate, but especially for Dr. Dean. Polls consistently show that voters believe Democratic priorities--schools, housing, job training, infrastructure--are underfunded. What balanced budget requirements do is force representatives to show what their priorities really are--and hold them acocuntable to the voters for the choices they make.
Bush has bought short-term prosperity and neutralized potentially hostile interest groups with policy giveaways we won't be paying for until well after the election. People vaguely sense a problem here, with the large expenses coming as the Boomers retire, but we need to concretize it. We need to make the case that this isn't responsible leadership (which folds into a larger potential theme for Dean and surrogates to hammer at in the general campaign).
Dean isn't going to outflank Bush on "God and gays" (at best, he can hope to neutralize him on the gun issue). And we wouldn't want him to. Basically he has to make the argument that it's more important to have a responsible leader who can manage America's resources and ably represent us in the wider world, than a man who looks pious or will cater to one's prejudices. The balanced-budget proposal--along with a really good tax reform plan that explains why Republican proposals don't do what people think they do--could be a big part of making this case.