fix(blog): correct centrist definition, contextualize metrics, add verdict at end

reports/overton_window/blog_post.html

@@ -527,7 +527,7 @@ The Overton window did not shift right. Right-wing parties moderated toward it.
 
 <h2>Can We Predict Which Motions Succeed?</h2>
 
-<p>A predictive model (logistic regression, AUC-ROC = 0.81) identifies the strongest predictors of centrist support:</p>
+<p>A predictive model (logistic regression, AUC-ROC = 0.81) identifies the strongest predictors of centrist support. Given the 6.9:1 class imbalance (only 14.5% of motions have high centrist support), this is meaningfully above the 0.50 baseline — the model reliably separates high-support from low-support motions.</p>
 
 <table>
 <tr><th>Feature</th><th>Coefficient</th><th>Interpretation</th></tr>
@@ -544,6 +544,12 @@ The Overton window did not shift right. Right-wing parties moderated toward it.
 
 <p>The Dutch political landscape post-2024 is not best described as "the Overton window shifted right." A more accurate description:</p>
 
+<p>The Overton window is often misunderstood as a fixed frame that parties push in one direction. What actually happened in the Netherlands is more subtle: right-wing parties discovered that the path to centrist acceptance runs through moderation, not radicalization. JA21 — not PVV — is the primary beneficiary of this strategy. The Christian-conservative center (CDA, ChristenUnie) was the primary enabler, more than doubling its support for migration motions. The progressive center (D66) barely moved.</p>
+
+<p>The spatial data tells us something important: this is not convergence. Centrists voted more with right-wing parties on right-wing motions while simultaneously moving further left in their overall voting patterns. The ideological distance widened. What changed was not where centrists sit on the political spectrum — it was what right-wing parties chose to propose.</p>
+
+<p>The temporal data adds a warning: the effect may be temporary. The 2026-Q1 reversion to 0.334 suggests the shift was driven by electoral dynamics (the PVV shock) rather than durable ideological realignment. If the pattern holds, the "new normal" may be closer to pre-shift levels than to the 2024-Q4 peak.</p>
+
 <ol style="margin: 1rem 0 1.5rem 1.5rem;">
   <li><strong>Right-wing parties strategically moderated.</strong> They filed more motions, with milder content, framed in centrist-friendly language. The share of high-impact proposals (M≥4) dropped from 23.7% to 11.3%.</li>
   <li><strong>Centrist parties rewarded the moderation.</strong> Support surged from 0.251 to 0.507, driven primarily by CDA and ChristenUnie on migration issues.</li>
@@ -556,15 +562,19 @@ The Overton window did not shift right. Right-wing parties moderated toward it.
 <strong>The critical caveat:</strong> This analysis establishes a structural break in centrist voting behavior, not its cause. The timing strongly supports an electoral explanation (before cabinet, after election), but this remains correlational. A proper causal design would require comparison groups we don't have.
 </div>
 
+<div class="verdict">
+The Overton window did not shift right. Right-wing parties moderated toward it. That moderation effect may be temporary.
+</div>
+
 <h2>Methodology</h2>
 
 <p>This analysis uses data from the Dutch Tweede Kamer OData API, covering 2,986 classified right-wing motions (2016–2026). Key methodological choices:</p>
 
 <ul style="margin: 1rem 0 1.5rem 1.5rem;">
-  <li><strong>Centrist definition:</strong> Strict: D66, CDA, ChristenUnie, NSC (not VVD or BBB).</li>
+  <li><strong>Centrist definition:</strong> VVD, D66, CDA, NSC, BBB, ChristenUnie — the six parties closest to the parliamentary center on the Procrustes-aligned SVD axes.</li>
   <li><strong>Extremity scoring:</strong> Two-dimensional (stylistic extremity + material impact), scored by LLM with manual validation (75% agreement). 2,869 motions scored (96% of total).</li>
   <li><strong>SVD alignment:</strong> Procrustes-aligned PCA with flip correction ensuring right-wing parties appear on the right.</li>
-  <li><strong>Mechanism classification:</strong> 200 motions classified by LLM, validated with inter-rater reliability (Cohen's κ = 0.41).</li>
+  <li><strong>Mechanism classification:</strong> 200 motions classified by LLM, validated with inter-rater reliability (Cohen's κ = 0.41 — moderate agreement, borderline; the taxonomy needs sharper category boundaries, particularly between institutional/rule-of-law and targeted restriction).</li>
   <li><strong>Statistical approach:</strong> Descriptive (Cohen's d) rather than inferential. Small-N time series (8 pre-2024 annual windows, 3 post-2024) limits the power of formal statistical tests.</li>
 </ul>