Constitution Preamble Clustering – NLP-Based Ideological Mapping

Explore how different constitutions express national ideals and values through their preambles.

This project analyzes the preambles of world constitutions using modern natural language processing (NLP) techniques to discover shared linguistic and philosophical themes. It visualizes countries clustered by their constitutional language into distinct categories of national identity and governance.

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Overview

Constitutional preambles serve as a window into a nation’s founding values and principles — from faith and unity to legality and progress. Using semantic embeddings and unsupervised clustering, this project identifies recurring ideological patterns and presents them through an interactive world map built with Streamlit and Plotly.

Live App

View Streamlit Dashboard

Full Notebook

01_data_preprocessing.ipynb

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Methodology

1. Text Cleaning & Preprocessing

   • Remove punctuation, numbers, and stop words.
   • Standardize text casing.
   • Prepare preambles for embedding.

2. Embedding

   • Model: SentenceTransformer('all-mpnet-base-v2')
   • Generates semantic vectors for each country's preamble.

3. Clustering

   • Algorithm: KMeans
   • Number of clusters determined via Elbow and Silhouette methods.
   • Chosen: 6 clusters

4. Dimensionality Reduction

   • Visualized in 2D space using PCA.

5. Visualization

   • Mapped using GeoPandas and Plotly Choropleth.
   • Interactive dashboard built in Streamlit.

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Cluster Summaries

Cluster	Description	Sample Countries
Legal-Institutional	Common-law or Commonwealth traditions emphasizing legality and institutional formality.	Australia, Canada, United Kingdom, France, Mexico
Unity & Pluralism	African constitutions stressing unity, dignity, and cultural pluralism.	South Africa, Kenya, Congo, Ethiopia
Faith & Founding	Constitutions emphasizing faith, moral values, social justice, and independence, mostly found in South America.	Argentina, Bolivia, Brazil, Chile, USA
Civic Republic	Influenced by USSR’s civic and renewal ideals emphasizing peace and responsibility.	India, Ukraine, Russia, Estonia
Religious-Administrative	Governance guided by religious principles and structured administrative order, mostly in Islamic nations.	Afghanistan, Pakistan, Iran, Iraq, Egypt
Collective Progress	Socialist or revolutionary constitutions centered on unity and collective progress.	Indonesia, Bangladesh, Bhutan, Thailand, China
Parliamentary-Administrative	European parliamentary and administrative constitutional systems.	Germany, Austria, Belgium, Norway, Italy

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Visualization

The Streamlit app displays an interactive world map where each country is colored by its constitutional cluster.

Features

• Hover to explore cluster membership and country name.
• Automatically scales to window size.
• Includes descriptive summaries for each cluster.

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Run Locally

1. Clone the repository

git clone https://github.com/ShailKPatel/Constitutional-Values.git
cd Constitutional-Values

2. Install dependencies

pip install -r requirements.txt

3. Run the Streamlit app

streamlit run app.py

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Technologies Used

Python – Data processing and clustering

Pandas / NumPy – Data manipulation

Sentence-Transformers – Text embeddings

scikit-learn – KMeans clustering & PCA

GeoPandas – Country geometries

Plotly – Interactive choropleth visualization

Streamlit – Web app interface

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Data Source

Elkins, Zachary, Tom Ginsburg, and James Melton. Comparative Constitutions Project (CCP).
https://comparativeconstitutionsproject.org/

Note:
The presence or absence of any country in this map is not an ideological or political statement.
The countries shown were selected solely based on their availability in the Comparative Constitutions Project (CCP) and the GeoPandas library.