Or, maybe I should have asked: Have the Republicans on the court become less ideological?
| Justice | Same-Party Agreement, % | Opposite-Party Agreement, % | Propensity to Same-Party Agreement |
| Roberts | 74.5 | 82.3 | 0.91 |
| Kennedy | 73.8 | 84.8 | 0.87 |
| Scalia | 76.5 | 74.3 | 1.03 |
| Alito | 77.3 | 75.3 | 1.03 |
| Thomas | 73.5 | 62 | 1.19 |
| Breyer | 92.7 | 82.5 | 1.12 |
| Ginsburg | 91.3 | 75.2 | 1.21 |
| Sotomayor | 91.3 | 74 | 1.23 |
| Kagan | 90.7 | 77.3 | 1.17 |
The numbers in the second and third columns are averages derived from Scotusblog (scroll down to the bottom). The last column is the second column divided by the third, so >1 means greater agreement with co-partisans.
Roberts and Kennedy are more likely to agree with the Democrats than with the other Republicans. I don’t think this has happened before. Last year, Roberts agreed with his co-partisans 88.8% of the time, and his opposite-partisans 81% of the time. For Kennedy, it was 86.8% and 82.25%. The Democrats and Thomas follow the ideologically polarized pattern of prior years.