In this projection, I am assuming a revote in both Florida and Michigan. As such, I have included current superdelegate endorsements from those states in superdelegate totals, and placed both their pledged and add-on delegates in the “remaining” column.
In order to win the nomination, Clinton needs to win at least 93 more delegates than Obama before the convention. If she does so, her delegates plus Edwards delegates will force a brokered convention, even if every single superdelegate makes an endorsement beforehand. That requires 53.8% of the remaining delegates. While difficult, that is certainly not impossible, especially if she goes on a winning streak starting in Pennsylvania. In order to win 50% +1 before the convention, she needs 687.5 delegates, or 56.0% of those that remain. While that is starting to enter highly unlikely territory, it is also a reason why she is starting to organize in multi-tiered delegate contests.