This Means MTM Theory Fails to Explain the Real Politics of SCOTUS Confirmations

In a surprising contradiction, this study questions whether Supreme Court nominations truly follow move-the-median (MTM) theory.

The article provides a fresh theoretical framework that synthesizes existing MTM models by accounting for two concerns: the location of the new median justice versus the ideology of the nominee herself. By using refined measurement and scaling techniques to align presidents, senators, and nominees on a common ideological axis, we can test diverse predictions from all model variants.

We find substantial evidence challenging core assumptions of MTM theory:

• • Presidents' Senate allies have consistently shown more accommodation than predicted by MTM models
• • Many nominees confirmed were less extreme than MTM anticipated
• • Conversely, presidents often selected nominees significantly more radical than what MTM would suggest was strategically optimal

These findings call into question the fundamental explanatory power of move-the-median theory in understanding confirmation politics and have profound implications for how political scientists interpret the ideological balance on the Supreme Court.