First, by cutting the number of delegates in half, the Party has essentially said that a Floridian's vote is worth half as much as say a Californian's. Second, the Party decided to give 40% of the votes of Michigan to Obama. This was a practical matter, because Obama was not on the ballot in Michigan. If he would have been, he would have probably done much better than that, but it is still wrong for the Party to decide how people voted, instead of letting people actually vote.
The other thing that I object to is all of this business about party unity. I hate that term, because I hate party unity. Party unity is the key to the two-party system that forces us all into picking the lesser of two evils. Let's take a look at the current Democratic contest. Obama does not do well with union workers, and what is wrong with that? Why does he have to do well with union workers? Oh, because if he doesn't get the support of union workers, minorities, women, etc. then he can't beat the Republicans' coalition of religious groups, nationalists, upper middle class, etc.
Personally I would love to see the Democratic Party break apart. I would also love to see the Republican Party break apart. I think it would be great to see coalitions formed on more of an issue-by-issue basis. Is there any doubt that we would already be out of Iraq if that was the case? I think most Republicans know it is a mistake to be there, but party unity subverts democracy. If we didn't have party unity, we could probably agree on some kind of pollution credit system to protect the environment.
Party unity is the key to the success of divisive politics. You can use such issues only when you are assured it will not cause you to lose votes from your own party -- i.e. only when you have party unity. Do you think Republicans would bring up things like abortion, immigration, and stem cell research if they thought that they might lose some of the upper middle class voters they count on? No way. But when you know that your own constintuency will still vote for you even when you bring up issues they disagree with you on, then you are free to be evil.