How to think about 170.6 challenges after J.O.

Every litigator has a judge or two they would paper on sight. The peremptory challenge under Code of Civil Procedure section 170.6 seemingly gives an absolute right: one affidavit, no reasons given, no questions asked, and the judge is gone. That’s how it’s been done for nearly 50 years. But not anymore. If you or your office make blanket challenges to a judge, the California Supreme Court in J.O. v. Superior Court (2026 WL 1488791) (S287285) holds your opponent may object, which could require you to explain your good faith reasons for the challenge.

Spurned by an admonition for one of its attorneys’ litigation conduct, the County Counsel’s office in the small San Joaquin County Superior Court made 325 challenges to the conservatorship judge in just four months. The sheer volume forced the court to reassign the judge to traffic court. The conserved party, J.O., objected that the 170.6 challenges were in bad faith, but the trial and appellate court, limited by the seemingly absolute statute, denied relief.

Those were the extreme facts that moved the Supreme Court to review and reverse.

A Legislative “concealed weapon.” Back in 1938, the court struck down a no-reasons peremptory as an unconstitutional interference with the courts—"a concealed weapon" against the judicial department (Austin v. Lambert (1938) 11 Cal.2d 73). The Legislature answered in 1957 with section 170.6's affidavit requirement: you must state under oath that the judge is prejudiced. The court upheld that version a year later, the oath being the difference. (Johnson v. Superior Court (1958) 50 Cal.2d 693.) The bargain was efficiency for honesty—no inquiry into the affidavit, in exchange for a sworn statement presumed—conclusively—to be true.

While blanket challenges occurred, Solberg held they were an "inconsequential price." In 1977, a deputy district attorney papered a municipal judge across a run of prostitution cases and argued the blanket practice violated the separation of powers. The court reaffirmed the statute and rejected the attack, calling abuse "a relatively inconsequential price to be paid" for an efficient procedure—and besides, the practice was "self-limiting" because it would antagonize the rest of the bench. (Solberg v. Superior Court (1977) 19 Cal.3d 182.) Justice Tobriner, in part, disagreed: the judiciary is not "helpless" against an abuse of its own process. Solberg won. Tobriner waited.

What changed. Over the next 49 years, felony filings roughly tripled, budgets got cut, judgeships went unfilled, and the trial bench fractured into specialized calendars—dependency, family, mental health, drug, veterans, CARE Act, Racial Justice Act. On a one-judge specialized calendar, papering that judge is no nuisance—it is a takeover. J.O. represents the Court’s changing its mind: blanket challenges, in these circumstances, are not longer inconsequential: they can "materially impair" a core judicial function—the presiding judge's authority to assign judges and run the court.

The new mechanism — Batson for judges. The court borrowed the three-step framework from jury selection (Batson v. Kentucky (1986) 476 U.S. 79):

1. The opponent of the 170.6 must timely object and make a prima facie showing of a bad-faith blanket policy. An objection by itself does nothing; without the showing, the challenge is granted without inquiry, the same as always.
2. If the showing lands, a different judge holds a hearing, and the burden shifts to the challenger to give a genuine, case-specific reason to believe this judge is prejudiced against this party.
3. That judge decides whether the reason is real or pretextual. Genuine, and the case is reassigned. Pretext, and the challenge is denied and the judge stays.

The pattern itself can carry step one. Persistent strikes against the same judge in all or a substantial portion of cases of a particular type, the court says, "may alone be persuasive." A spike in challenges after an adverse ruling, a written office policy, or an open-court admission all help.

A practical checklist.

What does this mean if you are making a 170.6 challenge? Or if you are objecting? Below are some things to keep in mind:

Making a 170.6:

• Just like always: File timely, in proper form, one per side, with the sworn statement of prejudice. Used as designed—one judge, one case, a real belief—nothing in J.O. touches you. The individual good-faith challenge survives.
• What’s new: Do not build a pattern. If your office reflexively papers the same judge, you are now assembling the other side's prima facie case for them.
• Stop doing this: Never say “I always paper Judge So-and-So.” Never tell yourself—or others—that Judge So-and-So is "likely to rule against [your] interests” on the evidence; or that you challenge the judge because of "prior rulings of law," or because of the judge's "views on the law or on the exercise of judicial discretion," or because of the judge's "personality traits."
• Do this instead: What does count as valid grounds is the judge's "mental attitude or disposition toward a party," without regard to the evidence.

Objecting to a 170.6:

• Object on the record and promptly. The trigger and the burden are both yours.
• Build the pattern: how many challenges, against which judge, over what period, in what category, and what preceded them — an adverse ruling, a sanctions finding, an admonishment. Concentration plus timing is the heart of the showing.
• Ask for the hearing before a different judge, and be ready to test whether the proffered case-specific reason is real or reverse-engineered after the fact.

The risk everyone will ask about. "I always challenge Judge X." Does that survive J.O.? If it is you, in your own cases, acting on a genuine belief formed from your own experience, yes—the single good-faith challenge is protected, and besides, one lawyer rarely generates a "blanket." The exposure is institutional and categorical: an office or a specialist firm that papers the one judge on a calendar, case after case. There, the good-faith belief must now be case-specific, and "I've had bad experiences with her" or "she's wrong on this area of law" will not survive step three. Volume plus a generic rationale is exactly what the new rule catches.

The loophole this closes. The real service of J.O. is shutting down institutional calendar capture. A public conservator that can paper out any judge who scrutinizes it gets to choose the judge who reviews its own conservatorship decisions—the watchdog picking its own watchdog. Probate and LPS calendars are especially exposed, because they so often run through a single judge. J.O. hands the presiding judge a tool to resist the takeover. For anyone who worries about conservatorship abuse, that is the decision working as it should.

The danger running the other way. The same rule can entrench a bad judge. In a small county where one long-tenured judge owns a calendar and rules with an iron fist, the local bar's only practical check has been the peremptory. After J.O., the lawyer who keeps challenging that judge—because experience says he should—now risks having those challenges branded a bad-faith pattern, with the burden on him to justify each one. The decision protects judicial independence by trimming a litigant's protection against a captured bench. In a two-judge county, that trade is not obviously worth it. Watch how the trial courts treat the repeat challenger who turns out to be right.

A closing puzzle. Here is what nags at me. J.O. rests on a muscular idea of "the judicial power"—a core function the Legislature may not materially impair. Hold that next to California standing law. Unlike the federal courts, ours have no constitutional "case or controversy" requirement; the Legislature largely decides who may sue, and our Supreme Court has said standing is not even jurisdictional. (Weatherford v. City of San Rafael (2017) 2 Cal.5th 1241; Save the Plastic Bag Coalition v. City of Manhattan Beach (2011) 52 Cal.4th 155.) So the court cedes to the Legislature the gatekeeping question—who may invoke the judicial power—yet guards its housekeeping—who sits on which calendar—as constitutionally sacrosanct. It gives away the front door and fortifies the back office.

That ordering should raise an eyebrow, and it has a practical edge. J.O. polices the shape of one tool. It does nothing to stop the Legislature from minting a different one—say, a statutory right for any party who "regularly appears" before a judge to seek reassignment on some lesser showing—and handing it to whomever it likes. With no constitutional standing floor, the judiciary would struggle to object to who gets the new key. The court even invited the Legislature to amend 170.6 as it sees fit. A separation-of-powers victory that depends on legislative forbearance is a fragile one. The full upshot is not yet clear. But a court that will not define the judicial power at the courthouse door stands on uncertain ground when it invokes that same power to govern the hallway.