Some legal experts say it is time to draw a sharp line between protected speech and harmful disinformation.The lawyers and First Amendment scholars who have made it their life’s work to defend the well-established but newly threatened constitutional protections for journalists don’t usually root for the media to lose in court.But that’s what is happening with a series of recent defamation lawsuits against right-wing outlets that legal experts say could be the most significant libel litigation in recent memory.The suits, which are being argued in several state and federal courts, accuse Project Veritas, Fox News, The Gateway Pundit, One America News and others of intentionally promoting and profiting from false claims of voter fraud during the 2020 election, and of smearing innocent civil servants and businesses in the process.If the outlets prevail, these experts say, the results will call into question more than a half-century of precedent that created a clear legal framework for establishing when news organizations can be held liable for publishing something that’s not true.Libel cases are difficult to prove in the United States. Among other things, public figures have to show that someone has published what the Supreme Court has called a “calculated falsehood” or acted with reckless disregard for the truth.But numerous First Amendment lawyers said they thought the odds were strong that at least one of these outlets would suffer a rare loss at trial, given the extensive and well-documented evidence against them.That “may well turn out to be a good thing,” said Lee Levine, a veteran First Amendment lawyer who has defended some of the biggest media outlets in the country in libel cases.The high legal bar to prove defamation had become an increasingly sore subject well before the 2020 election, mainly but not exclusively among conservatives, prompting calls to reconsider the broad legal immunity that has shielded journalists since the landmark 1964 Supreme Court decision New York Times v. Sullivan. Critics include politicians like former President Donald J. Trump and Sarah Palin, who lost a defamation suit against The Times last month and has asked for a new trial, as well as two Supreme Court justices, Clarence Thomas and Neil M. Gorsuch.Mr. Levine said a finding of liability in the cases making their way through the courts could demonstrate that the bar set by the Sullivan case did what it was supposed to: make it possible to punish the intentional or extremely reckless dissemination of false information while protecting the press from lawsuits over inadvertent errors.“If nothing else,” Mr. Levine added, “it would effectively rebut the recent contentions that the Sullivan regime doesn’t work as intended.”The Sullivan case, which legal scholars consider as seminal to the First Amendment as Brown v. Board of Education of Topeka was to civil rights, established the “actual malice” standard for defamation. It requires that a suing public figure prove a person or media outlet knew what it said was false or acted with “reckless disregard” for the high probability that it was wrong.Calls to weaken that precedent drew considerable resistance from advocates for press freedom. But many of them have come to see the threat of a defamation suit — a tactic often used by the powerful to retaliate against and mute unwelcome criticism — as an essential tool in the battle against disinformation.Increasingly, many First Amendment lawyers see the courts as one of the last viable paths to deter the spread of political disinformation and help prevent repeats of dangerous situations — from another Jan. 6-style riot to the more isolated threats against local officials that grew out of Mr. Trump’s false insistence that the election was stolen from him.“I think we are at a time in U.S. history and world history of losing any ability as a civilization to distinguish between truth and falsity,” said Rodney Smolla, a lawyer representing Dominion Voting Systems, a technology company suing Fox News and several individuals who promoted conspiracy theories about the last election, including Rudolph W. Giuliani and Sidney Powell.“And one of the few legal avenues in which civilized countries have attempted to distinguish between truth and falsity is defamation law,” said Mr. Smolla, who believes the Sullivan decision is sound law. A judge in Delaware, where the Dominion suit was filed, denied Fox’s motion to dismiss the case in December, and it is now in the discovery phase.As a defense, Fox and others invoke the First Amendment and Sullivan, arguing that their reporting on the 2020 election and its aftermath is legally indistinguishable from the kind of basic, just-the-facts journalism that news organizations have always produced. Fox has portrayed itself as a neutral observer, saying it did not endorse claims about hacked voting machines and systemic voter fraud but instead offered a platform for others to make statements that were unquestionably newsworthy.As Fox News mounts its defense in the Dominion case and in a lawsuit by another voting systems company, Smartmatic, the network’s lawyers have argued that core to the First Amendment is the ability to report on all newsworthy statements — even false ones — without having to assume responsibility for them.“The public had a right to know, and Fox had a right to cover,” its lawyers wrote. As for inviting guests who made fallacious claims and spun wild stories, the network — quoting the Sullivan decision — argued that “giving them a forum to make even groundless claims is part and parcel of the ‘uninhibited, robust and wide-open’ debate on matters of public concern.’”Last week, a federal judge ruled that the Smartmatic case against Fox could go forward, writing that at this point, “plaintiffs have pleaded facts sufficient to allow a jury to infer that Fox News acted with actual malice.”The broadness of the First Amendment has produced strange bedfellows in free speech cases. Typically, across the political spectrum there is a recognition that the cost of allowing unrestrained discourse in a free society includes getting things wrong sometimes. When a public interest group in Washington State sued Fox in 2020, alleging it “willfully and maliciously engaged in a campaign of deception and omission” about the coronavirus, many First Amendment scholars were critical on the grounds that being irresponsible is not the same as acting with actual malice. That lawsuit was dismissed.But many aren’t on Fox’s side this time. If the network prevails, some said, the argument that the actual malice standard is too onerous and needs to be reconsidered could be bolstered.“If Fox wins on these grounds, then really they will have moved the needle too far,” said George Freeman, executive director of the Media Law Resource Center and a former lawyer for The New York Times. News organizations, he added, have a responsibility when they publish something that they suspect could be false to do so neutrally and not appear to be endorsing it.Fox is arguing that its anchors did query and rebut the most outrageous allegations.Paul Clement, a lawyer defending Fox in the Smartmatic case, said one of the issues was whether requiring news outlets to treat their subjects in a skeptical way, even if their journalists doubt that someone is being truthful, was consistent with the First Amendment.“If you’re superskeptical, you’re covered, but if you express sympathy, then somehow you’re not?” Mr. Clement said. “To me, that seems fundamentally problematic and antithetical to First Amendment values.”One America News also faces a lawsuit accusing it of deliberately promoting and profiting from false claims of voter fraud. It has not yet responded to the suit.The New York TimesPerhaps the boldest in claiming that they were merely reporting on important events and so are protected by the First Amendment are Project Veritas and its founder, James O’Keefe. They are being sued for publishing and amplifying the claims of a postal worker in Erie, Pa., who implicated his boss in a plot to backdate mail-in ballots and help elect President Biden. An investigation found no evidence to support those claims.In legal briefs, lawyers for Mr. O’Keefe and Project Veritas have called their work “the stuff responsible journalism is made of” and claimed that the case would put “news-gathering itself on trial.” To bolster their argument, they cite examples of how Project Veritas worked in ways that would seem consistent with professional news reporting, including reaching out to the accused postal supervisor for comment twice. A lawyer representing Mr. O’Keefe had no comment.The lawsuit, however, paints a different picture from the “scrupulous” reporting that Project Veritas lawyers described. It recounts how, after the election, the outlet published multiple articles about someone it identified as a whistle-blower, Richard Hopkins, who came forward with accusations that the local postmaster, Robert Weisenbach, was a “Trump hater” and had ordered employees to backdate mail-in ballots to help Mr. Biden.But the lawsuit claims that Mr. Hopkins changed his recollection of events when postal inspectors questioned him, admitting that he did not know whether Mr. Weisenbach had directed anyone to backdate ballots. As for whether Mr. Weisenbach was really the “Trump hater” Mr. Hopkins made him out to be, Mr. Weisenbach said he had voted for Mr. Trump.In the complaint, Mr. Weisenbach’s lawyers argued that what Project Veritas had done “was not investigative journalism.” Rather, they said, “it was targeted character assassination” aimed at undermining public faith in democracy.“It has no place in our country,” the complaint added.Protect Democracy, a nonpartisan advocacy group representing Mr. Weisenbach, is also assisting two public employees in Georgia who were falsely accused of orchestrating voter fraud. The pair, a mother and daughter, are suing The Gateway Pundit and One America News over articles that accused them of helping fake a water main break at a Fulton County ballot counting center and then telling everyone to go home so they could add suitcases full of illegal ballots to Mr. Biden’s totals.OAN has not yet responded to the suit. Lawyers for The Gateway Pundit have denied the claims in court filings.Rachel Goodman, counsel for Protect Democracy, said this kind of litigation “makes clear that there are steep costs to recklessly or intentionally spreading fiction for political or personal profit.”“It reminds them that the speech standards that have governed the marketplace of ideas for decades apply to them, too,” Ms. Goodman added. More