President Trump’s  assertion, at a rally on Saturday, that District Attorney Alvin Bragg is seeking to strip him of his “constitutional right to talk” underscores how the First Amendment is entangled in politics and pornography alike. 

Mr. Trump, whose hush money trial begins on Monday at lower Manhattan, told  throngs in Pennsylvania that he “will be forced to sit fully gagged. I’m not allowed to talk.” The reference is to a prior restraint issued by the presiding judge, Juan Merchan. Such orders are constitutionally disfavored because they restrict speech, but allowable as a last resort. 

The Constitution ordains, in relevant part, that “Congress shall make no law … abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.” Any law or ruling that infringes on that command is subject to the strictest scrutiny.

Mr. Trump has increasingly invoked the First Amendment as a bulwark against prosecution. He argues that his racketeering case at Fulton County should be dismissed because his activities in Georgia were constitutionally protected. He has also cited the clause to counter the three gag orders he faces across different jurisdictions.  

That order bars the 45th president from criticizing potential jurors and witnesses, prosecutors apart from Mr. Bragg, and family members of court staff, like Judge Merchan’s daughter. Mr. Trump appeared to flirt with violating the edict on Saturday, calling Judge Merchan “corrupt” and asking why “disgraced attorney and felon Michael Cohen” has not been “prosecuted for LYING?”        

It was Cohen who arranged the $130,000 in payments to the pornography star, Stephanie Clifford, known as “Stormy Daniels,” from Mr. Trump. Mr. Bragg alleges that those receipts amount to falsification of business records, a misdemeanor. He is expected to argue that because they occurred during the denouement of the 2016 election, they also violated campaign finance laws. That makes Mr. Trump’s behavior felonious. Or at least that’s the theory.  

Those payments, Mr. Bragg argues, were a down payment in the form of a non-disclosure agreement, on keeping from the electorate a sexual encounter between Mr. Trump and Ms. Clifford that allegedly occurred in 2006, at a celebrity golf tournament at one of his  properties at Lake Tahoe. Ms. Clifford alleges that he invited her to appear on “The Apprentice.”

By the time that Ms. Clifford, who hails from Baton Rouge, met Mr. Trump, she had been acting in erotic films for two decades. She tells CBS that she responded to Mr. Trump’s overtures with incredulity, reckoning that  “NBC’s never gonna let, you know, an adult film star be on.” The year she met Mr. Trump, she was named an “Adult Movie Feature Entertainer of the Year” and last year Pornhub garlanded her with a “Lifetime Achievement Award.”

None of Ms. Clifford’s accolades would have been possible without the Supreme Court’s ruling that most pornography is protected by the First Amendment. It was not always so. The Comstock Act, from 1873, prohibited the distribution of obscene materials through the post. It was under that statute that the Irish novelist James Joyce’s “Ulyssess” was judged obscene and banned in 1921. 

In Roth v. United States, from 1957, the high court ruled that such content was not protected by the First Amendment if it was deemed “obscene.” In that case, a Galician born publisher and poet, Samuel Roth, was accused of distributing  “obscene, lewd, lascivious or filthy” materials. He would serve nine years in prison for, among other things, bringing to America pirated editions of the English writer D.H. Lawrence’s “Lady Chatterley’s Lover.”

Pornography of the type that Ms. Clifford created is not, under Miller v. California, considered “obscene.” To be categorized as such, and thus put outside the ambit of the First Amendment, it must “depict or describe patently offensive ‘hard core’ sexual conduct.” It also must lack “serious literary, artistic, political, or scientific value.” Child pornography is not protected. 

Just as obscene material, but not run of the mill pornography, is left in the constitutional cold, so is speech uttered criminally. The judge at Fulton County, Scott McAfee, explained his denial of Mr. Trump’s motion to dismiss  by explaining that “even core political speech addressing matters of public concern is not impenetrable from prosecution if allegedly used to further criminal activity.”