{
  "metric_id": "voteview_between_party_nominate_center_dist",
  "tag": "ELITE_IDEOLOGICAL_SEPARATION",
  "role": "adjacent polarization diagnostic \u2014 NOT validated full E2 fragmentation measurement",
  "status": "RESEARCH ONLY \u2014 no E2/L1/M1 scoring",
  "refresh": {
    "at_utc": "2026-09-10T03:54:39.374203+00:00",
    "at_pt": "2026-09-09T20:54:39-0700 PT",
    "note": "Recomputed from existing VoteView raw (no re-download). Cong 118 primary completed endpoint; 119 provisional if present.",
    "raw_reused": true
  },
  "source": {
    "url": "https://voteview.com/static/data/out/members/HSall_members.csv",
    "path": "/workspace/srp-observatory/data/raw/voteview/HSall_members.csv",
    "sha256": "aadf38febc4dad9e8f5cba7bac4c8290f2d96d550b34938c91ff5bd32c0be358",
    "bytes": 6201500,
    "retrieved_at_pt_from_provenance": "2026-09-09T10:17:48-0700 PT"
  },
  "method": {
    "formula": "dist = |median(nominate_dim1|D) - median(nominate_dim1|R)|",
    "robustness": "also |mean(D)-mean(R)| reported only as sensitivity",
    "parties": "party_code 100=Democrat, 200=Republican",
    "chambers": [
      "House",
      "Senate"
    ],
    "min_n_party": 5,
    "dedup": "one row per (congress,chamber,icpsr); first wins",
    "null_dim1_excluded": true,
    "primary_chamber": "House",
    "senate": "sensitivity"
  },
  "counts": {
    "rows_total": 190,
    "ok": 170,
    "partial_congress": 20,
    "missing_both": 0,
    "dup_keys_skipped": 0,
    "other_party_skipped": 7169,
    "null_dim1_or_bad": 150,
    "non_HS_rows_seen": 129,
    "ongoing_provisional": 2,
    "completed": 188
  },
  "temporal_policy": {
    "as_of_pt": "2026-09-09",
    "ongoing_congress": 119,
    "primary_completed_endpoint": 118,
    "note": "eligibility_flag=ok means party floors met (distinct members); it does NOT imply the Congress is temporally complete"
  },
  "house_cong100plus_PRIMARY_completed_through_118": {
    "n": 19,
    "first_cong": 100,
    "last_cong": 118,
    "first": 0.666,
    "last": 0.893,
    "min": 0.664,
    "max": 0.893,
    "mean": 0.7992894737,
    "median": 0.795,
    "delta_first_last": 0.227,
    "last5_mean": 0.8872,
    "first5_mean": 0.6957,
    "temporal_scope": "completed_only",
    "endpoint_role": "primary_completed"
  },
  "senate_cong100plus_PRIMARY_completed_through_118": {
    "n": 19,
    "first_cong": 100,
    "last_cong": 118,
    "first": 0.6155,
    "last": 0.882,
    "min": 0.6155,
    "max": 0.882,
    "mean": 0.7180263158,
    "median": 0.707,
    "delta_first_last": 0.2665,
    "last5_mean": 0.8225,
    "first5_mean": 0.636,
    "temporal_scope": "completed_only",
    "endpoint_role": "primary_completed"
  },
  "house_cong100plus_WITH_provisional_119": {
    "n": 20,
    "first_cong": 100,
    "last_cong": 119,
    "first": 0.666,
    "last": 0.9255,
    "min": 0.664,
    "max": 0.9255,
    "mean": 0.8056,
    "median": 0.798,
    "delta_first_last": 0.2595,
    "last5_mean": 0.8951,
    "first5_mean": 0.6957,
    "temporal_scope": "includes_provisional_ongoing",
    "endpoint_role": "includes_provisional",
    "DEPRECATED_NOTE": "includes provisional 119; prefer PRIMARY through 118 for endpoint claims"
  },
  "senate_cong100plus_WITH_provisional_119": {
    "n": 20,
    "first_cong": 100,
    "last_cong": 119,
    "first": 0.6155,
    "last": 0.915,
    "min": 0.6155,
    "max": 0.915,
    "mean": 0.727875,
    "median": 0.70775,
    "delta_first_last": 0.2995,
    "last5_mean": 0.8492,
    "first5_mean": 0.636,
    "temporal_scope": "includes_provisional_ongoing",
    "endpoint_role": "includes_provisional",
    "DEPRECATED_NOTE": "includes provisional 119; prefer PRIMARY through 118 for endpoint claims"
  },
  "house_cong100plus": {
    "n": 20,
    "first_cong": 100,
    "last_cong": 119,
    "first": 0.666,
    "last": 0.9255,
    "min": 0.664,
    "max": 0.9255,
    "mean": 0.8056,
    "median": 0.798,
    "delta_first_last": 0.2595,
    "last5_mean": 0.8951,
    "first5_mean": 0.6957,
    "temporal_scope": "includes_provisional_ongoing",
    "endpoint_role": "includes_provisional",
    "DEPRECATED_NOTE": "includes provisional 119; prefer house_cong100plus_PRIMARY_completed_through_118"
  },
  "senate_cong100plus": {
    "n": 20,
    "first_cong": 100,
    "last_cong": 119,
    "first": 0.6155,
    "last": 0.915,
    "min": 0.6155,
    "max": 0.915,
    "mean": 0.727875,
    "median": 0.70775,
    "delta_first_last": 0.2995,
    "last5_mean": 0.8492,
    "first5_mean": 0.636,
    "temporal_scope": "includes_provisional_ongoing",
    "endpoint_role": "includes_provisional",
    "DEPRECATED_NOTE": "includes provisional 119; prefer senate_cong100plus_PRIMARY_completed_through_118"
  },
  "recent_house_tail": {
    "115": 0.8895,
    "116": 0.8845,
    "117": 0.883,
    "118": 0.893
  },
  "recent_senate_tail": {
    "115": 0.8,
    "116": 0.801,
    "117": 0.848,
    "118": 0.882
  },
  "provisional_119": {
    "house": {
      "congress": 119,
      "chamber": "House",
      "n_D": 222,
      "n_R": 227,
      "median_dim1_D": -0.3955,
      "median_dim1_R": 0.53,
      "mean_dim1_D": -0.386248,
      "mean_dim1_R": 0.523709,
      "center_dist_median": 0.9255,
      "center_dist_mean_robustness": 0.909957,
      "eligibility_flag": "ok",
      "min_n_party": 5,
      "ongoing_congress": true,
      "temporal_completeness": "ongoing_provisional",
      "n_party_floor": 5,
      "n_party_unit": "distinct_icpsr_members_after_dedup",
      "endpoint_role": "provisional_ongoing"
    },
    "senate": {
      "congress": 119,
      "chamber": "Senate",
      "n_D": 45,
      "n_R": 57,
      "median_dim1_D": -0.357,
      "median_dim1_R": 0.558,
      "mean_dim1_D": -0.367,
      "mean_dim1_R": 0.553649,
      "center_dist_median": 0.915,
      "center_dist_mean_robustness": 0.920649,
      "eligibility_flag": "ok",
      "min_n_party": 5,
      "ongoing_congress": true,
      "temporal_completeness": "ongoing_provisional",
      "n_party_floor": 5,
      "n_party_unit": "distinct_icpsr_members_after_dedup",
      "endpoint_role": "provisional_ongoing"
    }
  },
  "authorization": {
    "score_authorized_E2": 0,
    "L1_untouched": true,
    "M1_unscored": true,
    "MODEL_CHANGE": "NO",
    "no_composites": true,
    "no_sign_flip": true,
    "N1_N2_partial_contrary_preserved": true,
    "N4_separate": true,
    "tag": "ELITE_IDEOLOGICAL_SEPARATION",
    "not_full_E2": true
  },
  "caveats": [
    "Rising center separation = ELITE_IDEOLOGICAL_SEPARATION / adjacent polarization diagnostic \u2014 NOT validated full E2 fragmentation.",
    "Does not undo N1 (within-party homogenization) or N2 (100\u2212unity fell) contrary evidence.",
    "Same VoteView roll-call family as N1 \u2014 not independent-system replication.",
    "Career NOMINATE hindsight understates short-horizon swings.",
    "Center separation \u2260 within-party factionalization.",
    "No composites with N1/N2/N4/FSI. No sign flip."
  ],
  "plain_english_finding": {
    "primary": "House D/R median dim1 centers moved from 0.666 (cong 100) \u2192 0.893 (cong 118); \u0394=+0.227.",
    "senate_sensitivity": "Senate 0.6155 \u2192 0.882 (cong 118); \u0394=+0.2665.",
    "provisional_119_note": "Cong 119 in file as ongoing/provisional (House 0.9255, Senate 0.915) \u2014 not an endpoint claim."
  },
  "computed_at_utc": "2026-09-10T03:54:39.374203+00:00"
}