The process by which the Democratic Party allocates delegates is complicated, so it's a good thing that CNN.com features this explainer. Unfortunately, their explanation is totally wrong. The Democrats only allocate 35 percent of the delegates based on the proportion of the statewide vote. The other 65 percent of the delegates are allocated to congressional districts, with the number of delegates per district varying (since congressional districts have the same population, I believe the variance has to do with how many people voted for John Kerry) from district to district. Then each congressional district has its delegates apportioned proportionately.
This is quite different from what CNN explained. Among other things, it impacts turnout strategy. If Congressional District Seven of State X is blanketed with snow and only 11 people turn out to vote, but all eleven vote for Candidate A, then Candidate A still gets all of CD7's delegates even if those eleven votes are the only votes A gets in a state where two million people vote.
CNN's system seems to me like one that would make more sense, but them's the breaks. You need to explain the real electoral system, not some more rational, easier-to-explain alternative system.
Matthew Yglesias is a former writer and editor at The Atlantic.