If you see the Democratic party change their rules for awarding delegates for the 2012 election, that's a sign that Hillary is back in play. The system as it stands now strongly favors candidates who can win supermajorities in traditionally Democratic districts. Say, for example, somebody who can pull 95% of the black vote.
This is long, but it describes how convoluted the process was, or is:
"So, just like at the state-by-state level, the number of delegates is allocated by the Democratic performance in each district. (Exactly how varies quite bit - based on one of four approved formulas.) Every district gets between three and seven delegates.
And if that's not enough, here's where it gets really interesting.
For starters, you need at least 15% of the vote to get any delegates at all. Once the sub-15% folks are removed from the equation (sorry, Mike Gravel), here's how the math works:
* In a three-delegate district, if you get 50% plus one, you get two delegates. (Yes, that's a huge bonus for winning by a single vote.)
* In a four-delegate district, however, a 51-49% outcome leads to a 2-2 split among delegates. Even a 60-40 split is still 2-2. The winning candidate has to get to 62.5% to earn a 3-1 split.
* In a five-delegate district, unless the winning candidate gets over 70% of vote, it's going to be a 3-2 split.
* In a six-delegate district, it's going to be a 3-3 split, unless the winning candidate gets over 58.4%, then it's a 4-2 split. 75% of the vote earns a 5-1 split.
And so on...
For the campaign managers out there, consider what this means in terms of GOTV strategy. If you're fairly certain you're going to handily win a congressional district, you send your resources somewhere else. That is, unless you think you're in range of one of the supermajority tiers that earns you another delegate.
Even more to the point, given the 50/50 nature of the fight between Clinton and Obama, almost all the congressional districts with an even number of delegates will be split evenly. It'll take a big win of 56% (for 8), 59% (for 6), or 63% (for 4) to earn an advantage.
So, the GOTV campaigns are almost certainly happening entirely in the odd-number delegate districts. That's a weird artifact of the process, to be sure."
http://www.blueoregon.com/2008/02/understanding-d.html