Simon Head in the New York Review of Books:
In 2003 I wrote in my The New Ruthless Economy that one of the great imponderables of the twenty-first century was how long it would take for the deteriorating economic circumstances of most Americans to become a dominant political issue. It has taken over ten years but it is now happening, and its most dramatic manifestation to date is the rise of Bernie Sanders. While many political commentators seem to have concluded that Hillary Clinton is the presumptive Democratic nominee, polls taken as recently as the third week of December show Sanders to be ahead by more than ten points in New Hampshire and within single-figure striking distance of her in Iowa, the other early primary state.
Though he continues to receive far less attention in the national media than Hillary Clinton or Donald Trump, Sanders is posing a powerful challenge not only to the Democratic establishment aligned with Hillary Clinton, but also the school of thought that assumes that the Democrats need an establishment candidate like Clinton to run a viable campaign for president. Why this should be happening right now is a mystery for historians to unravel. It could be the delayed effect of the Great Recession of 2007-2008, or of economists Thomas Piketty and Emmanuel Saez’s unmasking of the vast concentration of wealth among the top 1 percent and the 0.1 percent of Americans, or just the cumulative effect of years of disappointment for many American workers.
Such mass progressive awakenings have happened before. I remember taking part in antiwar demonstrations on the East and West coasts in the Fall and Winter of 1967–1968. I noticed that significant numbers of solid middle-class citizens were joining in, sometimes with strollers, children, and dogs in tow. I felt at the time that this was the writing on the wall for Lyndon Johnson, as indeed it turned out to be.
More here.