First of all: Wow.  Polling actually is a science, guys, despite how much people like to gripe about it, but crazy shit can and will happen anytime measuring people happens.  And hooooly shit did they get Michigan wrong.  Congratulations to Senator Sanders on the big win.  A combination of facts and wanton speculation follows:

• How have I lived in Indiana and Illinois for my entire life, visited Michigan frequently during that time (I have a fair amount of family up there) and I don’t recognize their state flag?  Also, that’s a crazily complicated state flag.
• Independent voters were about a third of both the Democratic and Republican vote.  On the Republican side they mostly voted the same way the Republicans did, but there was a clear split on the Democratic side– registered Democrats voted for Hillary by about the margin predicted by the polls, but independents went 71-28 for Bernie.  That right there is probably the difference.
• You may think “Oh, he’s going to gripe that the real Democrats voted for Hillary now!”  Nope.  I’ve said “Them’s the rules” to enough Bernie supporters this election (and, notably, to a ton of Clinton supporters in 2008) and now it’s Clinton’s turn.  Them’s the rules.  Independent voters get to vote in Michigan.  Deal widdit.
• I felt like Bernie won the debate on Sunday night, but didn’t think it was a blowout victory, and his worst moment (“Whites don’t know what it’s like to be poor”) was worse than her worst moment (hemming and hawing about fracking.)  That said, it clearly created some serious momentum for Sanders.  I do think the independents were what propelled his win, but he also did much better than previous states among black voters (30%) and he won solidly in Dearborn, indicating that Arab & Muslim voters are choosing the candidate who hasn’t been killing their relatives back in the old country recently.  There are a lot of “OMG Arabs voted for a JEW!” articles floating around; they’re dumb and presumptuous– as if every Arab is automatically an anti-Semite.  It’s not hard to understand why the Muslims might choose the more dovish candidate, guys.
• CNN appears to not have polled on when people decided who to vote for, which is too bad.  I’d love to see how much of a break toward Bernie there was among late deciders, and how many there were.
• All that said, and while the win is certainly a reason to celebrate for the Sanders fans among us: Sanders is now farther behind than he was last week, because he never bothered to go to Mississippi at all and Clinton ran up the score something scary there.  When Bernie Sanders gets beat in the 17-29 age group by 62-37, he’s gotten clobbered, and while winning Michigan is definitely a good thing, he won close, and the delegates are awarded proportionally.  Even if he ends up closer in the big three states on the 15th, or even if he wins one or two of them, he’s still got 200+ delegates to make up before we worry about the superdelegates.
• Shut up about the superdelegates.  If he manages to generate enough momentum that he closes that gap (and I still think it’s virtually impossible) they’ll come around.  Same thing happened in 2008.
• Hillary’s campaign, while mostly well-oiled, has shown the occasional tendency to panic.  She should probably try her damnedest to reign that impulse in this week, and make sure all of her spokespeople keep their damn yaps shut and don’t say a bunch of dumb shit either.  If Lynn Forester de Rothschild is still alive, tape her mouth shut and drop her in a ditch somewhere until after the primary is over.
• (Fact: two of her three most assholish surrogates from 2008, Harriet Christian and Geraldine Ferraro, actually are dead.)

I’ll add more stuff later if something else comes to mind.  For now, yell at me in comments if you feel so inclined.