Yglesias is hammering home the point that absent some clearly defined other plan, disability benefits would of course be cut in a Pozen-related plan. But, more than that, dependent benefits for widows and widowers with dependent children would also be seriously slashed, as they too are formula-linked to retirement benefits.
The dependent benefits has been the most ignored aspect of social security during this entire discussion, as the bamboozlers want to pretend that the big tragedy is the person who dies when their children are adults. But, for people who have dependent children, when one spouse (even in many cases divorced spouses) dies, social security really does frequently allow the rest of the family to maintain their current economic status. Cuts in retirement benefits would cut these benefits as well, plunging middle class people into poverty when a parent dies.