[I suggest first reading: 53rd Installment. State Bar v. Equal Protection of the Law.]
No judicial determination affecting an equal-protection action is more important than level of scrutiny. Most equal-protection cases fail, entitled only to the rational-basis standard, which the state trivially satisfies. An equal-protection action is entitled to strict scrutiny when the state actor impinges a First Amendment right, such as the right to petition. To bring a winnable equal-protection action based on State Bar discipline for court filings, the First Amendment right to petition comes into play subordinate to equal protection. A respondent's strict-scrutiny equal-protection case requires determining that: 1) the subject State Bar discipline impinges the right to petition; and 2) the impingement exclusively targets lawyers. (Cf. Rattray v. City of National City (9th Cir. 1994) 36 F.3d 1480, 1483 [analogous relationship of equal protection to privacy, instead of petition].) Notice that determination "1" suffices for strict scrutiny on the First Amendment issue itself, a potentially confusing observation because the 53rd Installment brought in the Fifth Amendment to supplement the untenable First Amendment approach. To solve the conundrum: A compelling state interest in regulating the court’s receipt of documents, consuming court time, justifies the restraint on speech.
To succeed with the present equal-protection and free-speech argument, you must allege impingement of protected speech. Don’t expect sustaining this allegation to be easy, as the court will try to categorize frivolous motions as unprotected, alongside obscenity and intentional lies. In a near-future Installment, I'll sketch a variant argument that can prevail without the court's determining that frivolous filings are protected speech, but proving that penalties for frivolous motions restrain protected speech isn't inherently hard apart from judicial bias, despite the absence of decisions addressing the categorization. Since “frivolous” describes the aim of a motion or action, a ban on frivolous proceedings prohibits a range of objectives. Since the ban takes sides against petitioning for objectives deemed frivolous, the speech restraint is viewpoint discriminatory, not content-neutral. Frivolous filings can be regulated only to satisfy a compelling state interest in procedural orderliness. But no compelling state interest requires prohibiting attorney disobedience to orders and rules when nonlawyers in propria persona have the right to test petitionability’s limits, subject only to milder contempt penalties.