One party's extremism is a trap you can only get out of if the other side decides to chill out first.
SSRN · March 18, 2026 · 6425039
The Takeaway
The paper identifies a 'moderation export' effect where a tiny shift in one party's voting base can trigger a sudden, discontinuous collapse of extremism in both parties. It suggests that radicalization isn't just an internal choice, but a mutual equilibrium where neither side can safely move toward the center alone.
From the abstract
With four political candidates competing first in two primaries and then in a general election, even a modestly polarized electorate can sustain (in equilibrium) much more extremist candidates. However, a party can sustain extremism only if the other side is extreme, too. A small moderation of one side’s voting electorate can trigger a discontinuous collapse of candidate extremism on both sides — a “moderation export” effect. The converse is also true: minute increases in voter polarization on t