Political polarization negatively impacts the impartiality of judicial appointments and erodes public trust in courts

What's this about?

People disagree about whether party conflict harms fair judge picks and makes people trust courts less.

What supporters say

• Party fights over naming and approving judges have grown sharper, so picks can seem tied to party goals.
• Studies link judges’ past beliefs, the presidents who picked them, and local politics to some court results.
• These links can shape who sits on courts and sometimes affect how courts rule.
• People often trust courts more when their own side wins and less when it loses.

What critics say

• A judge’s beliefs or past party links do not prove that the judge rules unfairly.
• Studies show links between politics and some rulings, but links do not show that one thing caused another.
• The Spain study showed lost support after court rulings, but it did not prove judge picks caused that loss.
• We should not assume that all judges put party goals ahead of the law.

The bottom line

Party conflict can make judge picks look less fair and can split public trust in courts. We are less sure that it broadly stops judges from ruling fairly.

Political polarization can make judicial appointments look more partisan and can push public views of courts into political camps. But the evidence is less clear that it broadly destroys judges’ ability to decide cases impartially.

The case for

The strongest evidence concerns how judges are chosen. Nomination and confirmation battles have become more polarized, with ideology and political signaling playing a larger role in how nominees are evaluated. That makes it difficult to view appointments as fully separate from partisan goals. 1

Research on U.S. federal appellate courts also finds that judges’ ideological backgrounds, the presidents who appointed them, home-state politics and polarized voting patterns are linked to some court outcomes. These studies do not show that judges are acting improperly. But they do show that political characteristics connected to appointments can shape the makeup of courts and, in some cases, their decisions. 2

The effect is especially visible in public attitudes. When nominations and major rulings become political flashpoints, people increasingly judge courts through the lens of whether their own side is winning or losing. Research on court legitimacy and confidence finds that partisan identity and “winner-loser” status strongly influence how citizens assess courts. In other words, trust can become dependent on political allegiance rather than on a shared view of the institution (see Figure 2). 3

Court rulings themselves can deepen this divide. Comparative research from Spain found that constitutional-court decisions during a polarized territorial conflict prompted backlash and reduced acceptance among politically mobilized groups. That study does not prove that appointments caused the loss of support. Still, it illustrates how courts can lose standing when their decisions are viewed as part of a wider partisan struggle. 4

The case against

The central caution is that ideological voting is not the same as biased judging. A link between a judge’s political background and a ruling does not prove that the judge favored a party, ignored the law or abandoned judicial independence. Legal rules, case facts, the other judges on a panel and institutional norms all constrain judicial behavior. 5

Much of the evidence also shows association rather than direct cause and effect. Studies can identify patterns between appointment-linked traits and rulings, but they cannot always establish that polarization caused a particular appointment, decision or loss of impartiality. Some of the relevant work is based on observational research, including working papers and preprints, which adds to that uncertainty.

Public confidence is also more complicated than a single approval rating. Long-term research finds substantial historical agreement in evaluations of the U.S. Supreme Court, while other scholarship treats legitimacy as a broader concept than approval alone. People may express low confidence after unpopular rulings, intense media coverage or changes in partisan control without rejecting courts as institutions. 6

That means declining approval may often reflect disagreement with outcomes rather than lasting distrust of the judiciary. Comparative research similarly suggests that confidence varies according to whether people see themselves as political winners or losers. Experimental findings also indicate that identity cues can shape perceptions of judicial fairness, meaning polarized appointments are not the only reason people may infer bias. 7

The bottom line

The evidence strongly supports the view that political polarization can politicize judicial appointments and make public assessments of courts more partisan. It also supports the finding that political and ideological factors are associated with some judicial outcomes.

But the evidence supports only a qualified claim that polarization undermines actual judicial impartiality. Political patterns in appointments and rulings should not be confused with proof that judges generally fail to apply the law fairly. Likewise, public trust appears to fall unevenly across political groups and circumstances, rather than collapsing uniformly.

Overall, the best-supported conclusion is that polarization more clearly damages the perception of neutrality and broad-based legitimacy than it proves a general loss of genuine judicial independence.