In 2005, MSNBC’s Chris Hayes published some remarkable journalism on his experience canvassing for John Kerry in Wisconsin, where voters didn’t seem to have any idea that their economic distress was something for which voting could make a difference.

“When I would tell them that Kerry had a plan to lower health-care premiums, they would respond in disbelief—not in disbelief that he had a plan, but that the cost of health care was a political issue,” Hayes reported. “It was as if you were telling them that Kerry was promising to extend summer into December.”

(. . .)

Data-driven analysis is only as good as the categories by which you sift the information. If you’ve already decided that “liberals” are the people who prefer locally sourced arugula to eating at McDonald’s, or are the people who don’t watch Fox News, it is a reasonable conclusion that there aren’t enough “liberals” out there to elect Bernie Sanders. Yet political categories shift. One of the things the best politicians do is work to shift them.

Sanders has been extraordinarily clear about the kind of shift he’d like to effect: Republicans “divide people on gay marriage. They divide people on abortion. They divide people on immigration. And what my job is, and it’s not just in blue states. . . [is] to bring working people together around an economic agenda that works. People are sick and tired of establishment politics; they are sick and tired of a politics in which candidates continue to represent the rich and the powerful.”