In North Carolina politics, the term “voter-suppression” gets bandied about quite a bit. But what if I told you there is a practice guaranteed to decrease voter participation in judicial elections by twenty percent?

It’s done by simply not including the party affiliation with state Supreme Court justice candidates on the ballot. By simply doing this, voting craters for these particular races.

And, unlike most claims of voter-suppression, the pernicious effect of making judicial elections nonpartisan is cleanly demonstrated by data.

A Natural Experiment Shows That Nonpartisan Elections Decrease Turnout

We have that data because the Democratic-controlled General Assembly switched from partisan to nonpartisan elections for North Carolina’s Supreme Court after Republican successes in races for those positions. Republicans later switched back to partisan Supreme Court races. That created a natural experiment on the effect of making judicial elections nonpartisan.

What does the data tell us?

The table below shows the dropoff from voting in presidential races to voting in North Carolina Supreme Court races in presidential election years from 2000 through 2020. The 2000 and 2020 elections had partisan Supreme Court races (with the candidates’ political parties by their names on the ballot). The Supreme Court races from 2004 through 2016 were nonpartisan. The 2004 and 2020 elections had multiple North Carolina Supreme Court races, so I took the average turnout.

The difference in dropoff between partisan and nonpartisan Supreme Court races is dramatic. The average decrease in partisan Supreme court races is 2.8 percent. For nonpartisan races, the average was 22.8%, which in the 2020 election would have been 1,259,655 fewer votes for the Supreme Court. In partisan years, that number would have been just 148,131. In other words, switching to nonpartisan judicial elections would have resulted in over a million fewer people voting in Supreme Court elections in 2020.

Nonpartisan Judicial Elections: Still a Bad Idea

Why do nonpartisan elections decrease voting? As Anthony Downs pointed out over half a century ago, a lack of information increases uncertainty about which candidates voters prefer. That uncertainly decreases voting.

With Republicans on the verge of retaking a majority on the state Supreme Court, a group of left-wing organizations is trying to bring back nonpartisan judicial elections. If they succeed, the only sure outcome would be that about a million fewer voters would participate in judicial elections.

Nonpartisan judicial elections were a bad idea 20 years ago and are still a bad idea today.