Under the rules, three-fourths of the pledged delegates are allocated by congressional district, the remaining one-quarter according to the vote statewide.
This leads to bizarre "everybody wins" results in the many congressional districts that have an even number of delegates. As a result, campaigns devote inordinate resources to districts that happen to have an odd number of delegates.
Consider a four-delegate district. For a candidate in a two-person contest to get three of the four, he would have to win a daunting 62.5 percent of the vote. The more likely outcome is that the winner and loser get two delegates each.
To obtain more than a one-delegate edge in a five-delegate district, the winning candidate would have to take 70 percent of the vote. The upshot: In a close race, it's extraordinarily difficult for one candidate to get very far ahead of the other.
The impact of this was clear in California, the biggest delegate prize. Clinton won43 of the state's 53 congressional districts, and 52 percent of the popular vote to Obama's 42 percent. But under the proportional representation rules, and with 32 of the districts offering an even number of delegates, she received 207 delegates to Obama's 163. Had Democrats used the Republicans' formula in California -- with delegates awarded on a winner-takes-all basis by congressional district and statewide -- Clinton would have received 316 delegates, Obama just 54.Marcus notes that neither the GOP nor the DEM system is "right" in some abstract sense: arguably the GOP gives too much weight to the winner, the Dems too little. But, she concludes:
As [Tad] Devine and [Anthony] Corrado explained in 1991, "the primary consequences of the move to proportional representation is that the
superdelegates now stand as the only bloc of delegates in which it may be possible to build an extraordinary delegate margin."