From this point, quick math shows that after Super Tuesday, only 1,428 pledged delegates will still be available. Now, here is where the problem shows up. According to current polling averages, the largest possible victory for either candidate on Super Tuesday will be Clinton 889 pledged delegates, to 799 pledged delegates for Obama. (In all likelihood, the winning margin will be lower than this, but using these numbers helps emphasize the seriousness of the situation.) As such, the largest possible pledged delegate margin Clinton can have after Super Tuesday is 937 to 862. (While it is possible Obama will lead in pledged delegates after Super Tuesday, it does not currently seem possible for Obama to have a larger lead than 75). That leaves Clinton 1,088 pledged delegates from clinching the nomination, with only 1,428 pledged delegates remaining. Thus, in order to win the nomination without the aid of super delegates, in her best-case scenario after Super Tuesday, Clinton would need to win 76.2% of all remaining pledged delegates. Given our proportional delegate system, there is simply no way that is going to happen unless Obama drops out.
So, there you have it. Unless either Obama or Clinton drops out before the convention, there is simply no way that the nominee can be determined without the super delegates. In the broadest definition of the term, "a brokered convention" is a convention that is determined by super delegates instead of nominating contests. Through a deadly combination of a primary calendar race to the bottom and an anachronistic method of delegate selection, we Democrats seem to have already arrived at that point. Short of one candidate dropping out, there is simply no easy way that this situation can be resolved. Given that Michigan and Florida combine for 313 pledged delegates, it is likely that this situation won't be resolved without severe bureaucratic fighting on the DNC rules and by-laws committee, or even a credential fight at the convention itself.
And why should either candidate drop out? Clinton has a large lead in super delegates, and can make a real argument over the Michigan and Florida delegations. Obama, by contrast, will probably lead in pledged delegates at the end of February, and will be able to raise significantly more money than Clinton. And so, we are at an impasse.
My instincts tell me this is a complete disaster, since it will shine light on complicated bylaws and the questionable democratic nature of the delegate selection process instead of on voters. As fascinating as it might be for political junkies, it is not the kind of image Democrats need. We need to figure a way out of this situation in a hurry.
Update: After some thought, the best solution I can come up with is to get a majority of super delegates to pledge to support whoever wins the majority of pledged delegates following the final primaries and caucuses in early June. To resolve the Michigan and Florida situations, simply allocate Florida's delegates as they would have been allocated according to the primary vote there. In the case of Michigan, do the same thing, except allocate according to the exit poll results that show how people would have voted if Obama had been on the ballot.
Our options are not pretty, but that would be better than letting bylaws and super delegates determine the nominee instead of voters. Hopefully, either Clinton or Obama will run up a long list of wins, and the other candidate will drop out. Failing that, hopefully the super delegates will line-up behind whoever has the most popular support and pledged delegates. Failing both, we could be facing a crisis in the party where the nominee lacks legitimacy in the opinion of the rank and file.