Four years ago this week, the Supreme Court ruled in Citizens United vs. Federal Election Commission that the First Amendment prevents the government from restricting independent campaign spending by corporations. The ruling unleashed a deluge of campaign spending that made 2012 by far the most expensive election cycle in history, with nearly $1.3 billion spent independently from candidates’ official campaigns.

We’ve all heard about the super-PACs and dark money nonprofit groups that have funneled millions from corporate and mega-rich donors into presidential and Congressional races, but now new research shows that outside spending has had a big impact on judicial races as well, raising concerns about state judges’ ability to remain impartial in a political world where hefty chunks of campaign cash can make or break elections.

Thirty-eight states hold elections for seats on their supreme courts, including both direct elections and up-or-down votes to retain judges initially appointed by governors or other state officials. In the post-Citizens United election season of 2012, many state judicial races looked a lot like the brutal campaigns waged for Congressional and presidential candidates, with super-PACs paying for vicious attack ads and special interests raising millions of dollars of campaign funds.

Writing in dissent of the Citizens […]