Topic: Center Squeeze (the eliminated moderate)¶
Topic hub — a cross-method view. Center squeeze is when a broadly-liked moderate — who would beat every rival head-to-head — is eliminated early for having too few first choices, handing the win to a more polarizing candidate the majority actually opposed.
The one idea to take away: center squeeze is specific to the Hare elimination rule (drop the fewest-first-choices candidate), not to ranked ballots, and not even to every instant-runoff variant. Read the whole ballot and the squeeze disappears.
Which methods suffer it — and where each is treated¶
| Method | Squeezes the center? | Why | Full page |
|---|---|---|---|
| RCV-IRV (Hare) | ❌ yes | eliminates on first choices, so the moderate is cut before their breadth counts | Center squeeze |
| Contingent / Supplementary | ❌ yes | one-shot top-two — same first-choice cut | Contingent & SV |
| BTR / Baldwin / Nanson | ✅ no | Condorcet-safe IRV variants — read the whole ballot | Which RCV-IRV? |
| Coombs | ✅ no | eliminates on last choices, so the moderate survives | Coombs |
| Ranked Robin / Condorcet | ✅ no | elects the head-to-head winner directly — never eliminates them | Ranked Robin |
| STAR | ✅ no | the scoring round advances a candidate on strength of support, not first-place counts | Center squeeze § how STAR avoids it |
The same 27-voter election runs through every method on the RCV-IRV-Hare page: Hare elects Left, everyone who reads the whole ballot elects the Condorcet winner, Center.
And it happened for real: Burlington 2009 — the actual 8,980 ballots, runnable in this repo. Montroll beats everyone head-to-head (5–0), IRV eliminates him in the semifinal, and a 750-voter raise built from the same profile makes the winner lose (non-monotonicity on certified ballots).
And the critique is ~240 years old. When the Marquis de Condorcet — the man the Condorcet criterion is named for — considered the eliminate-the-fewest-first-choices idea in the 1780s, he rejected it for exactly this flaw: that "the real wish of the plurality may be for a candidate who had none of the votes in the first ballot." Center squeeze, diagnosed two centuries before Burlington and Alaska made it concrete. (Via Wikipedia's IRV history; surfaced in Frohnmayer's Demystifying STAR Voting.)
Closely related: monotonicity and Condorcet efficiency. Glossary: center squeeze.
This is a topic hub (cross-method index). The authoritative write-ups live in the per-method folders linked above. See the topics index for the other topic hubs.