The Democratic primary is being defined—and could be decided—by a generational divide. Young voters are flocking to Bernie Sanders, as countless articles point out, and the results in Iowa back this up: Sanders won caucus voters under 30 by an astounding 70-point margin, while Hillary Clinton won those over 65 by 43 points. The theories given for this divide are myriad. Many young voters see Clinton as a corrupt or untrustworthy insider, whereas Sanders “seems sincere.” Many older voters, meanwhile, find Sanders’s policies impractical and see in Clinton a historic opportunity to elect the first female president. But all these arguments seem to agree on one thing: Sanders is leading a semi-socialist insurgency against the party establishment.

Surveying one hundred years of history, though, the question is not why younger voters are embracing Sanders’s populist revolution, but why the Baby Boomer generation came to believe that Bill and Hillary Clinton—with their close ties to big business—should become the standard-bearers for the nation’s liberal party. In other words, Bernie’s millennial army isn’t the generational exception. Hillary’s Boomers are.

Transported to the early part of the previous century, Sanders’s positions and rhetoric would sound a lot more traditionally Democratic than Clinton’s. Consider his New Hampshire victory speech, where he said, “Tonight, we served notice to the political and economic establishment of this country that the American people will not continue to accept a corrupt campaign finance system that is undermining American democracy, and we will not accept a rigged economy in which ordinary Americans work longer hours for lower wages, while almost all new income and wealth goes to the top 1 percent.” That’s much closer to progressive Democratic forebears like William Jennings Bryan (the party’s presidential nominee in 1896, 1900, and 1908) and Franklin Roosevelt (president from 1933 to 1945) than Hillary Clinton is.

What changed? The fundamental makeup of the American economy.

Adam Peck

Data from the Bureau of Labor Statistics makes clear how few professional options most people had in the first half of the twentieth century. In 1910, fewer than 15 percent of people worked in managerial or professional roles. The great majority worked in manual jobs, and had no ladder to climb.

