This misses the point in a rather fundamental way. Few people actually vote based on policy. As I recently argued in American Affairs, even the better educated don’t primarily vote based on policy. In fact, higher levels of education can increase polarization. (In other contexts, such as the Middle East, the advent of universal education and higher college attendance fueled ideological divides.) As the political scientist Lilliana Mason notes, “Political knowledge tends to increase the effects of identity as more knowledgeable people have more informational ammunition to counter argue any stories they don’t like.”

Derek Thompson: Alexandria Ocasio-Cortez has the better tax argument

People’s politics tend to determine their policy preferences, and not the other way around. In one example from the 1960s, as Christopher Achens and Larry Bartels write in Democracy for Realists, even southerners who supported racial integration left the Democratic Party. Once they became Republican, they then adjusted their views on race and affirmative action to fit more comfortably with their new partisan identity. Put another way, if a person with no prior partisan attachments decides to become a Republican, he is likely to become pro-life. If that same person, with the same genetics and life experience, decides to become a Democrat, he is likely to become pro-choice.

Ocasio-Cortez and other progressives appear to understand instinctually what this growing body of research on voter preferences suggests. And its implications are potentially far-reaching. Once you accept that voters are rationally irrational, you can’t help but change how you understand political competition. Incidentally, this is one reason that right-wing populists across Europe (and India and the Philippines and many other places) have been surprisingly—or unsurprisingly—successful: They seem to have relatively little interest in what works. Instead they are concerned with altering the political and ideological imagination of ordinary voters and elites alike, to make what once seemed impossible, possible. In their case, it often involves normalizing Islamophobia and other forms of bigotry. They have managed to drag the center-right further rightward on issues such as immigration and how to integrate (or not integrate) Muslim minorities. But this same approach can be used by left-wing and center-left parties for more constructive ends.

This focus on shifting the contours of the national debate is sometimes referred to as expanding the “Overton window.” It is altogether possible that Ocasio-Cortez doesn’t think that a 70 percent marginal tax rate is realistic in our lifetime—she might not even think it’s the best option from a narrow, technocratic perspective of economic performance—but it doesn’t need to be. As the Open Markets Institute’s Matt Stoller notes, “One thing that [Ocasio-Cortez] has shown is that political leadership matters. Just proposing a 70 percent marginal tax rate has restructured a debate over taxes. Obama’s presidency was defined by self-imposed limits.”