California Courts Can Now Ask Why You Keep Firing the Judge

Picture a lawsuit where the other side doesn’t like the judge. Not because the judge ruled against them on the merits, but because the judge once held them accountable. So they make the judge go away. Not from one case, but from every case like yours, filing the same boilerplate paperwork over and over until the court has no choice but to reassign that judge somewhere else. For nearly fifty years, California law said the courts were powerless to stop this. As of last week, that’s no longer true.

The California Supreme Court decided J.O. v. Superior Court on May 28, 2026, in a unanimous opinion authored by Justice Groban. The Court overruled part of a 1977 precedent and held, for the first time, that when a party abuses the judge-disqualification statute to force a particular judge off all of their cases in bad faith, a court can look behind the paperwork and ask what’s really going on. For anyone who litigates in California, and especially for anyone who litigates against an institutional opponent, the rules around judicial disqualification just shifted.

The Tool at the Center of the Case

California’s Code of Civil Procedure section 170.6 gives every litigant a powerful right. By signing an affidavit, or simply stating under oath, that a judge is “prejudiced” against them, a party can force that judge off the case. No proof required. No hearing. The disqualification is automatic, and a new judge gets assigned. The idea behind the rule is sound. Sometimes a litigant has a good-faith belief that a judge is biased but can’t prove it, and the law would rather remove the judge than force a party to litigate in front of someone they distrust.

The problem is what happens when the tool gets weaponized. If a district attorney’s office, a public defender, a county counsel, or even a private firm that handles most of one kind of case decides it wants a particular judge gone, it can file the same challenge in case after case. Done at scale, this isn’t about prejudice in any single case. It’s about removing a judge the office doesn’t like, often because the judge ruled against them once. Courts call this a “blanket challenge.”

What Happened Here

The petitioner, identified only as J.O., is under a conservatorship in San Joaquin County. According to the allegations, after Judge Erin E. Guy Castillo admonished a county counsel attorney for improper conduct, the county counsel’s office began disqualifying her across the board in conservatorship cases. Petitioner’s counsel estimates the office filed roughly 325 section 170.6 challenges against her in under four months. The result, as alleged, was that Judge Guy Castillo got reassigned out of the department handling mental health and conservatorship matters and into one hearing misdemeanors, traffic, and small claims.

The trial court felt its hands were tied. Under the 1977 precedent, Solberg v. Superior Court, blanket challenges were treated as immune from this kind of constitutional objection, so the court rejected the challenge to the practice without ever examining whether it was made in bad faith. The Court of Appeal denied relief. The Supreme Court took the case to decide whether Solberg still held up.

The Big Move

It doesn’t, at least not on this point. The Court explained that the judiciary of 1977 looks nothing like the one operating today. Caseloads have ballooned. In 1977 there were about 54,000 felony filings statewide. In the most recent year measured, there were nearly 180,000. Courts now run specialized calendars for things like conservatorships, family law, and drug and mental health treatment, all of which depend on assigning judges with particular training. Budgets are tighter and judicial vacancies are real. In that environment, letting a party force a specialized judge off an entire category of cases does real damage to the court’s ability to run itself.

That damage, the Court held, is a separation of powers problem. The California Constitution gives the judiciary, through the presiding judge, the authority to assign its own judges. When a litigant uses blanket challenges in bad faith to override those assignments, it lets one party effectively seize a function the Constitution reserves for the courts. So the Court overruled Solberg to the extent it barred courts from examining blanket abuses, while leaving the statute itself, and every good-faith individual challenge, fully intact.

How It Works Now

The Court borrowed the familiar burden-shifting framework from jury-selection challenges. First, the party opposing a section 170.6 motion has to timely object and make a preliminary showing that the other side is lodging bad-faith blanket challenges, often by pointing to a pattern of repeated strikes against the same judge after an adverse ruling. If that showing is made, the burden shifts to the party that filed the challenge to give a genuine, case-specific reason for believing the judge is prejudiced. Then the court decides whether the challenge was made in good faith or as part of a bad-faith blanket policy. A single good-faith challenge is still automatic and still requires no proof. Only the abusive, across-the-board pattern is now open to scrutiny.

One detail worth noting for civil practitioners. The Court made clear this applies to everyone, not just prosecutors. A private law firm that handles the bulk of a particular kind of case in a small county could just as easily abuse the statute to push out the one judge hearing those matters. The constitutional problem comes from the conduct, not the identity of the party.

What This Means for Litigants

If you litigate in California, the integrity of who hears your case just got a little more protected. The practice of quietly running a judge off the bench by paper, which has frustrated courts for decades, now has a check on it. Institutional players who relied on blanket challenges as a strategic tool need to rethink that approach, because the affidavit that used to be unreviewable can now be examined when a pattern of bad faith is shown.

At the same time, the Court was careful about what it did not do. It did not touch the facial validity of section 170.6, and it rejected an amicus proposal to bar government attorneys from using the statute at all, calling that solution a step too far. Your right to disqualify a judge you genuinely believe is biased, in your own case, is exactly where it was. What changed is the ability to weaponize that right across an entire docket.

The Bottom Line

J.O. v. Superior Court restores a piece of authority the courts thought they had lost. For most litigants, the practical takeaway is reassurance that the forum is harder to manipulate. For institutional and high-volume litigants who treated blanket challenges as part of the playbook, the takeaway is a warning. The pattern that used to be invisible is now something a court can be asked to examine, and the time to reassess that strategy is before the objection lands, not after.

If your matter involves questions about judicial assignment, disqualification, or litigating against a repeat institutional opponent in California, this decision may affect how you plan your approach. Reach out to Horst Legal Counsel to talk through what it means for your case.