Well, from the looks of the poll, he will gain about 3% on the number of blacks, and lose about 2% on the number of latinos, so, I do think he'll need over 40% of the white vote. But this is a pretty meaningless number, only the states matter.
The only numbers that matter are the ones that seem to benefit Clinton, be they delegates, states won, or popular vote totals in states her campaign agreed not to count.
Thanks, Jonathan for another great post. If not for you, I would have stopped reading this blog altogether. It's like politics through the looking glass.