There’s little argument that inequality, and the depressed prospects for the middle class, will be a dominant issue this year’s election. Yet the most powerful force shaping this reality—the rising cost of housing—has barely emerged as political issue.

As demonstrated in a recent report (PDF) from Chapman University’s Center for Demographics and Policy, housing now takes the largest share of family costs, while expenditures on food, apparel, and transportation have dropped or stayed about the same. In 2015, the rise in housing costs essentially swallowed savings gains made elsewhere, notably, savings on the cost of energy. The real estate consultancy Zillow predicts housing inflation will only worsen this year.

Driven in part by potential buyers being forced into the apartment market, rents have risen to a point that they now compose the largest share of income in modern U.S. history. Since 1990, renters’ income has been stagnant, while inflation-adjusted rents have soared 14.7 percent. Given the large shortfall in housing production—down not only since the 2007 recession but also by almost a quarter between 2011 and 2015—the trend toward ever higher prices and greater levels of unaffordability seems all but inevitable.