On this week’s edition of Last Week Tonight with John Oliver, Oliver discussed the public election of judges, a practice that occurs in all but 11 states. “The problem with an elected judiciary,” he explained, “is that sometimes the right decision is neither easy nor popular, and yet campaigns force judges to look over their shoulder on every ruling.”

Elected judges are susceptible to public opinion and attack ads, leading some to hand down tougher sentences during election years, according to Alicia Bannon of the Brennan Center for Justice, who appears in Oliver’s essay. (Read Bannon’s recent op-ed on the issue for BillMoyers.com). These excessively harsh rulings only further fuel the mass incarceration rates that give the United States the largest prison population in the world.

Oliver poked fun at hokey, low-budget judicial campaign ads that have nothing to do with the candidate or race at hand. But some ads do more serious damage: In one, which Oliver called misleading and “downright horrifying,” actors portraying violent offenders recount their gruesome crimes and claim the incumbent judge sided with them over law enforcement and their victims.

Not only can judicial elections spur harsher rulings, they also put judges at the mercy of campaign contributors. As Oliver pointed out, “Judges asking lawyers to give them campaign money is the definition of a conflict of interest.” Can a judge really make impartial decisions in a case where one of the parties or attorneys donated (or declined to donate) to the judge’s election campaign? The Supreme Court is currently considering the constitutionality of direct campaign solicitation by judges in Williams-Yulee v. Florida Bar.

Oliver closes the segment by reminding us that “faith in a strong, independent judiciary is essential for a civilized society.”

“If we’re going to keep electing judges, we may have to alter our idea of what justice is.”

(Warning: Mature language.)