We've been seeing a lot of discussion of what happens if Clinton forces a floor fight over the MI and FL delegations. I thought it'd be worth gaming out what such a floor fight would look like.
What is the floor fight based on? Under Article 2, section 2 of the Democratic Party Charter, "The National Convetion is the highest authority of the Democratic Party, subject to the provisions of this Charter." That means that a floor vote of the convention delegates supersedes any rulings by any DNC committee. A lot thus depends on which delegates are seated at the time of the convetion. Let's play this out two ways: one if MI and FL remain unseated (we'll call this the current situation), and one for the most likely compromise: one that seats the MI and FL delegations but gives them 0.5 votes each.
The delegates at stake are 73 pledged delegates from MI for Clinton, 55 "uncommitted" delegates from Michigan, (who have been chosen and are Obama partisans, so they'd effectively be unpledged Obama delegates), 113 Clinton FL delegates, 74 Obama FL delegates, and 11 Edwards FL delegates. Adding in unpledged delegates who have made commitments, Clinton has 15, and Obama 10, with 30 still uncommitted or unselected.
There are three scenarios to consider:
(1) Obama gets enough delegates that he can seat the delegations in full without affecting the result. In this case, there's no point to a floor fight; Obama can just be generous and seat the delegates by acclamation, and effusively praise Clinton's hard work in the defense of the delegates.
(2) Clinton gets a bare majority, even without the extra delegates. In this (unlikely, but numerically possible) case, again, there's no floor fight.
(3) Obama wins, but the result would be reversed if the FL or MI delegates were seated in full. At this point, a floor fight is nuclear war—you'll see angry walkouts by delegates, denunciations of everyone by everyone, and gleeful reporters describing the collapse of the Democratic party. If the superdelegates have any job at all, it's trying to avoid this scenario, by whatever means necessary.
So, what are the cutoff points? (I'll round up all numbers)
In the current situation, the "magic number" to win is 2,025. If you fully seat MI and FL, the magic number becomes 2,216. At half-strength, the magic number is 2,121.
Thus, to get into scenario (1) from the current situation, Obama needs 95 more delegates. Clinton still needs 244 to get into scenario (2). Any number between that leads to situation (3).
If the credentials committee half-seats FL and MI, then Clinton needs 239 delegates to get into situation (2). Obama's magic number remains the same (remember, to avoid nuclear war, Obama always has to win in the "seat everyone" scenario, while Clinton just needs to win in whatever scenario prevails.
Note that as soon as Obama gets 43 more delegates, (or 69 more, if the delegates from MI and FL are half-seated), he can win any floor fight. If he wants to actually avoid a floor fight, though, he needs the above numbers.
(And now I wait to find out if I botched the computations...)
[EDITED TO REMOVE CONFUSION BETWEEN 2 AND 3]