2969665423_cb5861053f_zYesterday, we addressed swing voter patterns at the Illinois Supreme Court between 2005 and 2009. Today, we turn to agreement rates between the Justices during the final five years of our study period, 2010 to 2014.

The Court’s unanimity rate between 2010 and today presents us with a bit of a conundrum. In 2010 and 2011, the Court decided more than seventy percent of its civil cases unanimously, but in 2012 and 2013, the Court’s unanimity rate abruptly dropped nearly twenty points. During the first two terms of 2014, the Court’s unanimity rate has risen back to its trend level of 77.8%.

The reason for the two-year dip in the Court’s unanimity rate is not evident from examining the Court’s voting patterns during the final five years of our study period. Chief Justice Garman had a high agreement rate with Justices Thomas and Karmeier, Justice Burke and increasingly, Justice Theis. Justices Thomas and Karmeier both had quite high agreement rates with their fellow Republican Justices. Justice Theis voted even more often with Justice Garman in our three-year floating averages for 2013 and 2014 – nearly eighty percent of the time.

Table 35 A

Chief Justice Kilbride and Justice Freeman were the two leading dissenters on the Court, with relatively low agreement rates with the other Justices:

Table 35 B

Since three-year floating averages do not reflect the reason for the sharp dip in 2012-2013 in the Court’s unanimity rate, we turn to the single-year statistics. This data suggests that rather that the two voting blocs – Justices Garman, Thomas, Karmeier, Burke and Theis and Chief Justice Kilbride and Justice Freeman – remained relatively steady during these two years. Instead, the decrease in unanimity appears to have been the result of the two voting blocs moving further apart, agreeing with each other less often.

Table 36

Next week, we’ll conclude our study of the 2010-2014 period by considering the data on swing voting patterns. Then, we’ll begin the next phase of our study of the Court’s civil decision making.

Image courtesy of Flickr by Kelley Minars (no changes).