i think that what you're seeing is just classic ballot box stuffing in the city districts - cook county & downtown boston were the ones with the biggest psychological outcomes (although, have a little patience with the pacifists, because it's the delegate count that matters and whether bernie carries a state with 55 or loses it with 45 doesn't matter a lot, even if it adds up - he's not behind because he lost illinois, he's behind because he got beaten in the southeast, and he has to find somewhere where he can win by similar margins to balance it out) to this point, but i think we've also seen it in cleveland, detroit, atlanta and, now, phoenix.
the way this works is that she floods the early voting results with mail-in and absentee ballots. this tactic was very clear in both ohio and arizona (as well as illinois and missouri), where the initial results came in with her up around 75-25. she's basically giving herself a huge head start - 50,000+ votes. then, when the actual votes come in, they have to make up the difference. and, you can add in the voter suppression tactics on top of this.
what that means is that there really isn't a conspiracy with the exit polls. you claim the data is staying put all night. this isn't actually the case, from what i've seen. rather, the margins get closer and closer all night. and, that is actually a classic sign of data-rigging.
in fact, the reason the networks are calling it so early is that they would expect - if the votes are fair - that the early voting would be roughly the same as the late voting. if the networks were looking for it, they would notice that the results that they're seeing are very suspicious - they shouldn't be watching the tallies narrow predictably over and over. an election where clinton gets 75% with early voters and 40% with day-of voters is just about the most obvious fraud you could contemplate. but, that is, in fact, what we're seeing, in state after state.
but, you have to understand that clinton can't do this by herself. this is a full party effort. and, what it means is that the party had already chosen it's candidate before the voting started, and the outcome was never in doubt. the party is just expecting sanders to act as bait. that's all this process ever was about. sanders will not be the democratic nominee, and the idea that he ever would be was never seriously on the table.
the thing is that sanders has to know this. what you're going to find out in the next few weeks is whether he's been playing along, and was just doing outreach for hillary the whole time, or whether this was a plan from the start to use the democratic primary as a launching pad for a run as an independent.
for right now? she's no doubt going to pull the same trick in seattle. he should get something like 75% in washington, but it will probably roughly split due to early voting mail-ins. and, the race will be officially done. you'll have to see what he does, next.
*washington is not an open primary, but an open caucus. that changes everything. it is easy to see that i would have suggested a large sanders win is most likely if i thought it was a caucus.