Right-wing television news outlets that amplified team Trump’s conspiracy theories about the 2020 election lost two key rulings in court this week that set the stage for a protracted battle between some of the biggest names in the American press and the technology companies behind voting systems in dozens of states.

A judge in Delaware ruled Tuesday that there is sufficient evidence that Fox’s chairman, Rupert Murdoch, and his son, Lachlan Murdoch, chief executive of Fox News’s parent company, played a direct role in post-election coverage on the news channel that Dominion Voting Systems alleges was defamatory and cost it tens of millions of dollars in business.

Dominion is seeking $1.6 billion in damages from Fox, and billions more from other players in President Trump’s attempts to have the election overturned.

The judge, Eric Davis of the Delaware Superior Court, where the lawsuit was filed, ruled that it was reasonable to conclude based on evidence presented by Dominion that the Murdochs acted with “actual malice” when they encouraged Fox News to repeat Mr. Trump’s claims about election fraud.

The judge wrote that “Rupert and Lachlan Murdoch either knew Dominion had not manipulated the election or at least recklessly disregarded the truth when they allegedly caused Fox News to propagate its claims about Dominion.”

The language used by the judge is critical to the lawsuit’s path forward. Under American case law, public figures and companies must prove that someone acted with malice — that they knew what they were saying was false and “recklessly” disregarded the truth when repeating it — for a lawsuit to proceed.

A First Amendment lawyer, Harvey Silverglate of Boston, said he was surprised that the judge issued such an opinion before both parties have had a chance to depose witnesses. “This judge has jumped the gun,” Mr. Silverglate said. “This is the kind of case that has to go to trial and cannot be decided on the papers.

“If the allegations are proven true, then it is a pretty clear case of defamation,” he added. “But that will require discovery and a trial.”

Last week, Judge Davis denied a motion by Newsmax to have a separate $1.6 billion lawsuit Dominion brought against it thrown out. Newsmax, according to Dominion, “helped create and cultivate an alternate reality where up is down, pigs have wings, and Dominion engaged in a colossal fraud to steal the presidency from Donald Trump by rigging the vote.”

A rival of Dominion’s in the voting technology space, Smartmatic, also got a green light — in this case from a federal judge — on Tuesday in its lawsuit against One America News Network, which accused the company of colluding with Dominion even though Smartmatic’s technology was used in only one county in America during the 2020 election cycle.

Both Fox News and Newsmax have said in court filings that their reporting is speech protected by the First Amendment and that statements by on-air personalities were opinion and also protected. It is much harder to win a libel case over an opinion.

Dominion and Smartmatic have sued most of the major names attached to the campaign to overturn the election in the fall of 2020, including lawyers Rudy Giuliani and Sidney Powell, the MyPillow CEO, Mike Lindell, two Fox News hosts, Jeanine Pirro and Maria Bartiromo, and a former Overstock CEO, Patrick Byrne. Dominion has not ruled out the possibility of suing Mr. Trump himself.

In its case against Fox News, Dominion asserts that both Murdochs allowed falsehoods about the company to be repeated on Fox in order to bring back viewers who had deserted it in favor of more conservative rivals and to boost the company’s bottom line. Mr. Silverglate said such a tactic could be a dangerous one for the plaintiffs.

“Motives are very complicated. People change their minds,” he said. “The judge is making an assumption of cynicism rather than giving the Murdochs credit for flexibility.”

Newsmax and One America News leaned hardest into the post-election fraud conspiracies, repeatedly alleging that Dominion employees and local election workers were in cahoots and flipped millions of votes in President Biden’s favor. A cabal of “globalists” funded by the Chinese Communist Party was, they reported, behind the conspiracy, which, they suggested, could be traced ultimately back to Venezuela’s former dictator, Hugo Chavez.

The fallout from the assertions was on display during this week’s congressional hearings about the January 6, 2021, riot on Capitol Hill. A Georgia election official, Gabriel Sterling, recalled being flabbergasted when he saw a tweet threatening a Dominion contractor that said,  “You committed treason. May God have mercy on your soul,” accompanied by a “slowly twisting GIF of a noose.”

Earlier in the hearing, Attorney General Bill Barr testified that he also dismissed the allegations against Dominion during conversations with his colleagues in the White House before he resigned in December 2020.

“I told them it was crazy stuff and they were wasting their time on it, and they were doing a great disservice to the country,” Mr. Barr said of the Dominion charges. “I saw absolutely zero basis for the allegations, but they were made in such a sensational way that they obviously were influencing a lot of people.”

Dominion said in court filings that it received multiple death threats and that it was forced to spend $600,000 on security for its employees after a brick was thrown through a window at one of its offices.

Election officials in states that use Dominion machines also reported receiving threats and calls to cancel contracts with the company. A $100 million contract in Louisiana was axed, according to one state official, because of “damage to voter confidence done by those who willfully spread misinformation and disinformation.”

In all, Dominion said it has lost at least $70 million in potential profits and would suffer financially for years because the reporting by Fox News and Newsmax was allegedly inaccurate.