This column is not ignoring Sen. Barack Obama's contention that Hillary Clinton refuses to say how she'd fix Social Security ... it's just the old brain has no original thoughts to add to the scrum.

Also, tomorrow night's debate is certainly going to advance this charge one way or the other.

The challenge is not whether Obama can or will say Hillary Clinton's name or whether he will find something to pick at her about. It's whether he can connect his charge to the larger argument he is making. And so far, that larger argument is largely devoid of direct references to Hillary Clinton. There is a thin backbone of a litany; there is no repitition of charges; no sustained chain of logic to persuade Democrats to reject Hillary Clinton and replace her with Barack Obama.

John Edwards makes just such an argument. Privately, it's electability. Publicly, it's that she represents corruption and compromise. So far, it doesn't seem to be working. Or maybe the press won't cover it. Or maybe the argument isn't precisely the right argument.

Polling shows that Democrats have yet to be persuaded that Clinton represents the dark side of the party. Even in the states where she polls below 30%, she is the first and second choice of a majority. (So is Obama). Electability seems to be the only question that Democrats do voice. Perhaps as the caucus and primaries draw nearer, those doubts will increase. Or, perhaps by that time, they won't exist.