The Democrats were also once again fuming and fighting over their presidential nominating rules in an escalating war that senior advisers say threatens to divide the party and damage its prospects in November.

These rules have forced the Democratic National Committee to strip Florida and Michigan of its delegates to the national convention, triggering charges of disenfranchising millions of their voters; empowered 795 superdelegates to pick a nominee in the event of a deadlock, regardless of the primary results; and raised questions about the efficacy of a long-drawn-out, proportional, delegate-selection process that may not produce a nominee before the convention in August.

If Democratic leaders cannot clean up this mess, the result "would be a disaster for the party which would be a very divisive floor fight and a lot of bitter feelings about whoever gets the nomination that somehow it was stolen by a backroom deal," said former Clinton White House chief of staff Leon Panetta.

Panetta, who is supporting Clinton, told me that the party needs to seat the Florida and Michigan delegates in a way that is seen as fair to both candidates -- a goal that seems beyond reach for now.

Over the long haul, "the whole primary system needs to be re-examined," he said. "We need to have a regional system rather than have states fighting to be first in line. We ought to move to a winner-take-all primary process. It's a cleaner approach to have someone win a primary, and it's fair. A majority vote usually wins in our system of democracy."

The specter of a bunch of superdelegates in smoke-filled rooms deciding who the nominee will be bothers many Democrats who fear it will poison the party's nominating process and hurt its chances in the fall.

"I don't think anyone envisioned that the superdelegates would decide who the nominee would be. I think that's a big difficulty, but we can talk about it after the election," said New Hampshire Democratic chairman Ray Buckley.

As things stand now, it appears neither candidate can reach the magic 2,025 delegates needed to clinch the nomination in the primaries. But if Obama's delegate lead holds, the proportional system Panetta wants to scrap will keep him ahead of Clinton to the end.

Then, in a scenario Democratic leaders fear most, the remaining 300 or so unpledged superdelegates will decide who wins. It could get very ugly.