Zero.
Senator Sanders now needs to capture approximately 69% of all remaining pledged delegates in order to achieve a bare majority of the pledged delegates.
2026 pledged delegates are needed for a bare majority.
Senator Sanders currently has either 1501 or 1500 pledged delegates. He needs another 525 or 526 pledged delegates for a bare majority.
There are 781 pledged delegates left to allocate from the remaining contests. Both 525 and 526 divided by 781 come to about 69%.
Putting aside his home state of Vermont, Senator Sanders best delegate haul in terms of percentage of delegates awarded to date was in New Hampshire, where Senator Sanders received 15 of the available 24 pledged delegates, or 62.5% of the available pledged delegates.
None of the remaining contests are “winner take all” (except for the theoretical possibility of one candidate not meeting the incremental threshold in the 3 remaining caucus jurisdictions — Virgin Islands, Puerto Rico, and North Dakota — incremental thresholds are 14.29%, 5.00%, and 16.67% respectively).
Based upon the results in all contests to date, what’s most likely to happen is that the remaining contests will result in a relatively even split of the remaining delegates.
If that happens, Secretary Clinton will end up with somewhere around 2160 pledged delegates (current 1770 plus 390), and Senator Sanders will end up with somewhere around 1891 pledged delegates (current 1500 plus 391).
2383 of all delegates — pledged and super — are required for nomination.
There are 712 super delegates. The current super delegate count in 543 for Secretary Clinton, 44 for Senator Sanders, 125 currently uncommitted.
If one assumes an even split of the remaining pledged delegates, Senator Sanders will need at least 492 super delegates to support him, which would be approximately 69% of all super delegates.
To achieve 492 super delegates, Senator Sanders will have to capture all 125 uncommitted super delegates, and will have to flip 323 super delegates who have already declared their support for Secretary Clinton.
Current delegate counts taken from 538 and Real Clear Politics.