How Bernie Sanders beat the polls and won Indiana

For the second week in a row, there was a temporary glitch in the Associated Press’s election night data. On Tuesday, that glitch was to Hillary Clinton’s favor, showing her with 2,000 more votes in Vigo County, Indiana, than she actually had. That gave Clinton a giant margin in early returns, vastly at odds with what exit polls showed — and far bigger than the 7-point margin she enjoyed in the final polling average from Real Clear Politics.

Within minutes, the wrong numbers in Vigo County was erased, and, over the next hour or so, Clinton’s remaining lead started to vanish. It wasn’t until about two hours after polls closed — at about the same time that Ted Cruz dropped out of the Republican race —- all but handing the nomination to Donald Trump — that the race in Indiana was called for Bernie Sanders. He’d beaten the polls, as he did in nearby Michigan — and probably, once all the votes are in, by a wider margin.

After losing five of six races over the last two weeks and only winning the small state of Rhode Island, the Indiana win was no doubt a welcome psychological boost. But why did Sanders win Michigan and Indiana, while losing other Midwestern states like Missouri (narrowly), Illinois and Ohio?

Unlike in the Republican contests, there have been pretty consistent patterns that have defined the Democratic match-ups. Bernie Sanders consistently does better with younger and more liberal voters; Clinton does better with older, more moderate and black voters.