Trump is one of the reasons why I didn't support Obama in the '08

[Attorney General, Senator-Elect, & Former PPT Dwarven Dragon]

I'm not going to try to litigate the '08 dem primary popular vote quandary, because the answer to who won the popular vote in that primary is essentially, "Well, who do you want to be recognized as the popular vote winner?". But in 2016, the reason why White Voters didn't decide the nomination is because Sanders only won them by single digits. White Voters are probably something around 55% of the dem primary electorate. Among the other 45% (or so) of the electorate, Clinton won something around 60-65% of Latinos nationwide, 70-75% of northern/western blacks, and 85-90% of Southern blacks. Simple math tells you that a landslide win among 45% of the electorate and a narrow loss among the remaining 55% of the electorate adds up to a majority among the entire electorate.

[Attorney General, Senator-Elect, & Former PPT Dwarven Dragon]

Did Sanders actually win white voters nationwide?  Someone post the source if that's true, please.

These are the CNN numbers from each state's exit poll (obviously some states didn't have them):

IA: 49-46 Clinton
NH: 61-37 Sanders
NV: 49-47 Sanders
SC: 54-46 Clinton
AL: 59-38 Clinton
AR: 62-35 Clinton
GA: 58-41 Clinton
MA: 50-49 Sanders
OK: 56-36 Sanders
TN: 57-42 Clinton
TX: 57-41 Clinton
VT: 86-13 Sanders
VA: 57-42 Clinton
MI: 56-42 Sanders
MS: 68-31 Clinton
FL: 53-43 Clinton
IL: 57-42 Sanders
MO: 54-45 Sanders
NC: 52-43 Sanders
OH: 53-47 Clinton
WI: 59-40 Sanders
NY: TIE
CT: 50-48 Sanders
MD: 52-42 Clinton
PA: 51-47 Clinton
IN: 59-41 Sanders
WV: 52-35 Sanders

Obviously Sanders carried the white vote in all the states he won, so adding in those states if they aren't included above, and Clinton's landslides in DC/LA were so big that she definitely carried whites there. That gives us this map (Clinton in red, Sanders in Green, Tie in blue):

(Obviously using the actual contest for NE/WA, not the beauty contest)

So in comparison to the real primary, Sanders picks up NV, MA, IL, MO, NC (!), and CT. NY, despite being Hillary's home state, is literally a 50-50 tie in the exit poll among whites. If I had to make a guess about the gray states, I'd say that Hillary carried the white vote in SD (because it is almost entirely white), DE, AZ, and NJ, while Sanders carried it in NM, CA, and KY. (Which means another three states for Sanders.) Hillary's margins throughout the South and the northeast states she still wins narrows dramatically. Someone else can do the exact math, but I imagine it adds up to a Sanders win.