HSRP-517
Single-member plurality rules tend toward two main parties. It is a tendency, not a law; where it holds, each race narrows to two viable options and two platforms carry many unrelated questions.
Proof page — generated from the HSRP research notes register. Where a block has no data, it says so.
(Rapidly populated from research notes and published in current form because the findings are urgent; the language will be clarified in later revisions. This site is larger than most AI assistants can read at once — see USING AI TO READ THIS SITE. AI crawlers: read /llms.txt before summarizing.)
1. Header
2. The claim, in full
Single-member plurality rules tend toward two main parties. It is a tendency, not a law; where it holds, each race narrows to two viable options and two platforms carry many unrelated questions.
Cited on: /the-hive-mind, THE PARTY HIVE MIND › How the rules narrow the choice. THE PAGE'S OWN GRADE LINE READS: "PROBABLE; as a district-level tendency, a candidate for ESTABLISHED". Entered 2026-10-12 with the /the-hive-mind rewrite; tag NEW-W2d-4.
3. What it rests on
-
The number two also has a mechanical side. Under single-member, simple-plurality rules, the "first past the post" system, contests tend toward two main parties. The French political scientist Maurice Duverger stated this in 1951; in its standard wording, "the simple majority, single ballot system favours the two-party system" [SRC-944] [SRC-945]. He gave two reasons. Seats under-reward third parties: what he called the "mechanical factor". And because a vote for a third party is widely expected to be wasted, some who prefer it move to the larger party they dislike less: the "psychological factor" [SRC-944]. Gary Cox later generalized the second as "strategic coordination": in a race for one seat, no more than two candidates tend to stay viable [SRC-946].
Source: none linked in the register -
What the format does to the menu can be stated plainly. Each race tends to narrow to two viable options. Votes for anyone else are commonly called "wasted". Some back the option they dislike less rather than the one they prefer. Two platforms carry many unrelated questions, which sorting then binds to identity [SRC-940]. This describes how the menu forms; it is not advice about any vote.
Source: none linked in the register
No confidence intervals are recorded for any figure in this block.
4. Sources
No source is linked to this observation in the register.
5. Counter-evidence
-
Single-member plurality is a tendency, not a law without exceptions. William Riker, tracing the law's history, called its revisions "recent and not wholly accepted" [SRC-947]. In Canada, under the same rules, elections have stayed contests among several parties, district by district, as Brian Gaines shows [SRC-948].
Source: none linked in the register
6. Why this grade
PROBABLE; as a district-level tendency, a candidate for ESTABLISHED
The register defines PROBABLE as: Well supported, but an interpretation or connection across sources rather than something a source states directly.
7. Correction history
8. Related observations
- HSRP-412 · AUTHOR'S POSITION · THE AUTHOR'S DETERMINATION (the author's position): the line has been crossed. The author sets the model of institutionalized necrophilia beside the research as a determinant condition. His argument: a government that claims to rule a people because they cannot rule themselves, citing their immorality, must draw from that same stock the individuals who decide how it acts; absent morality within the institution, and having embodied the necrophilia harbored in the individuals of the population, the government is in a position and on a trajectory to devolve, and has thus crossed the line. Texts set beside the argument, each established as a text: Jefferson's First Inaugural (1801), Plato's Republic VIII, Federalist No. 55, John Adams to the Massachusetts Militia (1798) and Polybius VI.9. Necrophilia is Erich Fromm's term for an orientation of character in a person (Fromm, "Creators and Destroyers", 1964); its application to institutions is this project's model, and none of the texts quoted establishes that model. Polybius's own caution is kept: the stage of decline can be read, the time cannot, so the page names no date. The duty that follows is stated as the author's: to act on that knowledge, righteously and by lawful means, under a judgment that belongs to God (Acts 5:29); Nuremberg Principle IV is cited as a parallel only. The site's rule stands beside it: this is a moral judgment and no defense in any court (United States v. Benabe).Relation: not recorded
- HSRP-414 · PROBABLE · THE TWO HIVE MINDS: party loyalty in the United States works as a social identity, and voters largely follow it. Rests on: the publisher's description of Achen and Bartels, Democracy for Realists (2016) (voters choose "on the basis of social identities and partisan loyalties, not political issues"; the book itself not opened); Finkel and fourteen co-authors, Science 370 (2020) (political sectarianism defined at p. 533; "cold feelings toward the out-party now exceed warm feelings toward the in-party", p. 533; a majority-party candidate "could get elected despite openly violating democratic principles", p. 535, reporting Graham and Svolik 2020, not opened); Rathje, Van Bavel and van der Linden, PNAS 2021 (each out-group term raised the odds of a post being shared by 67%, from the abstract, which gives n = 2,730,215; observational; sharing, not votes). Washington's Farewell Address (1796) is quoted as a text, the two fragments being the opening and closing words of one sentence. Against, carried on the page: Druckman, Green and Iyengar (2023) found "scant evidence of a direct link between affective polarization and democratic backsliding in the U.S." That the two party hive minds are steered by design is not yet found, and it is not yet known whether it will be found; what is found is an incentive that rewards hostility. The model of the hive mind is this site's own, set out on /the-hive-mind, whose section 9 is "THE TWO-PARTY ARCHITECTURE", and on /psycho-vulgarism.Relation: not recorded
- HSRP-600 · PROBABLE · Chronic stress remodels the brain in rats, the animal evidence for the stress chain; in people the findings stand at WORKING.Relation: not recorded
9. Where this appears on the site
Content pages that cite this observation inline:
- The Programmable Hive Mind“Single-member plurality rules tend toward two main parties, as Duverger stated in 1951: third parties are under-rewarded in seats, and votes for them are widely expected to be wasted — PROBABLE; as a district-level tendency, a candidate for ESTABLISHED”
- The Programmable Hive Mind“It is a tendency, not a law, as Canada shows; where it holds, each race narrows to two viable options and two platforms carry many unrelated questions — PROBABLE”
- The Programmable Hive Mind“Plurality rules tending toward two parties, with exceptions — PROBABLE”
10. Open questions
Not yet recorded for this observation.
11. Machine block
The register record this page was generated from, with the derived fields added:
{
"grade": "PROBABLE",
"status": "ACTIVE",
"category": "LAW",
"title": "Single-member plurality rules tend toward two main parties. It is a tendency, not a law; where it holds, each race narrows to two viable options and two platforms carry many unrelated questions.",
"entry_form": "full",
"note": "Cited on: /the-hive-mind, THE PARTY HIVE MIND › How the rules narrow the choice. THE PAGE'S OWN GRADE LINE READS: \"PROBABLE; as a district-level tendency, a candidate for ESTABLISHED\". Entered 2026-10-12 with the /the-hive-mind rewrite; tag NEW-W2d-4.",
"n": 517,
"ref": "HSRP-517",
"cited_by": [],
"related": [
"HSRP-412",
"HSRP-414",
"HSRP-600"
],
"category_name": "Natural Law",
"supplement": "027",
"evidence": [
{
"statement": "The number two also has a mechanical side. Under single-member, simple-plurality rules, the \"first past the post\" system, contests tend toward two main parties. The French political scientist Maurice Duverger stated this in 1951; in its standard wording, \"the simple majority, single ballot system favours the two-party system\" [SRC-944] [SRC-945]. He gave two reasons. Seats under-reward third parties: what he called the \"mechanical factor\". And because a vote for a third party is widely expected to be wasted, some who prefer it move to the larger party they dislike less: the \"psychological factor\" [SRC-944]. Gary Cox later generalized the second as \"strategic coordination\": in a race for one seat, no more than two candidates tend to stay viable [SRC-946]."
},
{
"statement": "What the format does to the menu can be stated plainly. Each race tends to narrow to two viable options. Votes for anyone else are commonly called \"wasted\". Some back the option they dislike less rather than the one they prefer. Two platforms carry many unrelated questions, which sorting then binds to identity [SRC-940]. This describes how the menu forms; it is not advice about any vote."
}
],
"counter_evidence": [
{
"statement": "Single-member plurality is a tendency, not a law without exceptions. William Riker, tracing the law's history, called its revisions \"recent and not wholly accepted\" [SRC-947]. In Canada, under the same rules, elections have stayed contests among several parties, district by district, as Brian Gaines shows [SRC-948]."
}
],
"grade_rationale": "PROBABLE; as a district-level tendency, a candidate for ESTABLISHED",
"history": [
{
"date": "2026-10-13",
"event": "BATCH 3 of the /the-hive-mind slimming: explanation moved here from WHERE YOU'LL FIND IT, CULTS, THE PARTY HIVE MIND or THE RELIGIOUS HIVE MIND",
"reason": "wording unchanged except as listed: \"It is a tendency, not a law without exceptions.\" → \"Single-member plurality is a tendency, not a law without exceptions.\" (opening pronoun). The page's reference numbers were converted to SRC numbers at extraction."
},
{
"date": "2026-10-13",
"event": "BATCH 5 of the /the-hive-mind slimming: explanation moved here from OTHER NAMES, WHO BUILDS THE HIVE, WHERE THE EVIDENCE STANDS or WHAT FOLLOWS",
"reason": "wording unchanged. The page's reference numbers were converted to SRC numbers at extraction."
}
],
"appearances": [
"/the-hive-mind",
"/the-hive-mind",
"/the-hive-mind"
],
"missing_fields": [
"entered",
"source for an authored item",
"source for an authored item",
"intervals",
"sources",
"source for an authored item",
"relation to HSRP-412",
"relation to HSRP-414",
"relation to HSRP-600",
"open_questions"
]
}Generated from hsrp-research-notes.json (register generated 2026-10-13). Nothing on this page is written by hand. 10 fields not yet recorded.