In this post and the next, we’re concluding our review of the Court’s unanimity rate in civil cases set against changes in the Court’s party alignment.
Despite changes in four of the Court’s seven seats during these eleven years, the party alignment of the Court remained the same throughout – four Democrats, three Republicans. As we see in the Table, although the number bounced around just a bit, it remained fairly steady throughout. In 2010, 72.73% of civil cases were unanimous decisions. In 2011, that figure was 76.32%. We then saw a two-year drop, to 55% in 2012 and 58.82% in 2013, before it returned to its trend level and stayed there: 77.78% in 2014, 79.55% in 2015, 75% in 2016, 80.77% in 2017, 63.64% in 2018, 70.59% in 2019 and 78.13% in 2020.
In our next post, we’ll take a look at the Justices who served on the Court during these years and look at their rate of voting with the majority. This should show which Justices were the drivers of the dip in unanimity in 2012 and 2013.