To win the majority of pledged delegates, currently Sanders needs to win 58.6% of the remaining pledged delegates, outside any gaming of caucus delegates.
In today’s five primaries, 384 pledged delegates are at stake, over 50% more than the NY total last week (247). That large total, coupled with the fact that with Clinton’s NY win she is 139 pledged delegates closer to the goal, with fewer delegates still on the table, and that she in favored in all 5 contests today, means that the path ahead for Sanders has gotten exponentially steeper.
The graph above shows the delegate share that Sanders will need as a function of Clinton’s outcome today. She needs just 41.4% to remain even. But based on current polls she could possibly get 60% of the delegates today. That would increase Sanders’ required share going forward from 59% to almost 66%.