A number of factors underpin the anti-redistributionist shift in public opinion that I wrote about last week.

First, and perhaps most important, is the emergence of significant resistance to downward redistribution among the elderly, a major voting bloc.

The views of older voters deserve scrutiny. They “worry that redistribution will come at their expense, in particular via cuts to Medicare,” Vivekinan Ashok, a Ph.D. candidate in political science at Yale; Ilyana Kuziemko, a professor of economics at Princeton; and Ebonya Washington, a professor of economics at Yale, write in a March 2015 Brookings Institution essay, “Support for Redistribution in an Age of Rising Inequality”— an essay my Times colleague Neil Irwin also discussed in a recent column that asked why Americans don’t want to soak the rich.

In the end, Ashok, Kuziemko and Washington conclude that

the elderly have grown increasingly opposed to government provision of health insurance and that controlling for this tendency explains roughly half of their declining relative support of redistribution.

What the Brookings essay neglects to explore are the material circumstances of over-65 voters that might affect their views on redistribution. Over a third of retirees depend on Social Security for 90 percent or more of their annual income, according to the Social Security Administration. In the zero-sum competition for federal dollars, the cost of major spending programs like the Affordable Care Act has to be made up by spending cuts elsewhere.