For the better part of a decade, Donald J. Trump and his allies at Fox News have beguiled some Americans and enraged others as they spun up an alternative world where elections turned on fraud, one political party oppressed another, and one man stood against his detractors to carry his version of truth to an adoring electorate.

Then this week, on two consecutive days, the former president and the highest-rated cable news channel were delivered a dose of reality by the American legal system.

On Thursday, Mr. Trump became the first former president in history to be indicted on criminal charges, after a Manhattan grand jury’s examination of hush money paid to a pornographic film actress in the final days of the 2016 election.

The next day, a judge in Delaware Superior Court concluded that Fox hosts and guests had repeatedly made false claims about voting machines and their supposed role in a fictitious plot to steal the 2020 election, and that Dominion Voting Systems’ $1.6 billion defamation lawsuit against the network should go to trial.

Both defendants dispute the claims. Still, the back-to-back blows against twin titans of American politics landed as a reminder of the still-unfolding reckoning with the tumult of the Trump presidency.

For the left, the seismic week delivered an “I told you so” years in the making. Democrats who have long wanted Mr. Trump criminally charged got the satisfaction of watching a prosecutor and a grand jury agree.

A day later, after years of arguing that Fox News was hardly fair and balanced, they could read a judge’s finding that Fox had not conducted “good-faith, disinterested reporting” on Dominion. Fox argues that statements made on air alleging election fraud are protected by the First Amendment.

While the two cases have nothing in common in substance, they share a rare and powerful potential. In both, any final judgments will be rendered in a courtroom and not by bickering pundits on cable news and editorial pages.

“There will always be a remnant, no matter how the matter is resolved in court, who will refuse to accept the judgment,” said Norman Eisen, a government ethics lawyer who served as special counsel to the House Judiciary Committee during Mr. Trump’s first impeachment. “But when you look at other post-upheaval societies, judicial processes reduce factions down to a few hard-core believers.”

He added, “A series of court cases and judgments can break the fever.”

That, of course, could prove to be a Democrat’s wishful thinking.

In this moment of constant campaigning and tribal partisanship, even the courts have had difficulty puncturing the ideological bubbles that Mr. Trump and Fox News pundits have created. The legal system produced a $25 million settlement of fraud charges against Trump University, dismissed dozens of lies about malfeasance in the 2020 election, pressed for the search for missing classified documents and ruled numerous times that Dominion’s machines did not in fact change votes.

Yet hundreds of thousands of Americans remain devoted to both defendants.

Embarrassing and damaging material has already come out through both cases, with little immediate sign of backlash.

Thousands of text messages, emails and other internal company documents disclosed to Dominion and released publicly portray high-level figures at the network as bent on maintaining ratings supremacy by giving audiences what they wanted, regardless of the truth.

Texts show the star prime time host Tucker Carlson calling Mr. Trump a “demonic force,” and the chairman of Fox Corporation, Rupert Murdoch, describing Sean Hannity as “privately disgusted by Trump.”

Fox News has said Dominion took private conversations out of context. Its ratings dominance appears untouched by the negative headlines in recent weeks. Data from Nielsen show that in March the 10 top-rated cable shows in America were all on Fox News, led by “Tucker Carlson Tonight,” and that 14 of the top 20 were produced by the network.

Still, experts believe the case has already resonated.

“I’ve never seen a case before where journalists said they didn’t believe the story they were telling but were going to keep telling it because it’s what the audience wanted to hear,” said Lyrissa Lidsky, a professor of constitutional law at the University of Florida and an expert on defamation law. “It’s a shock wave saying it’s time to get serious about accountability.”

Democrats, too, could see their illusions fall. Although many have clamored to see Mr. Trump charged, and felt vindicated this week, the risks of failure are considerable.

If Mr. Trump’s lawyers file to have the charges simply dismissed as prosecutorial overreach and quickly win, the consequences would almost certainly strengthen Mr. Trump, who will make the case — and possibly others to follow — central to his primary campaign.

But in a court of law, the magnetism that Mr. Trump and Fox News have over their audiences may lose some of its power. No matter how many times the former president insists outside the courtroom that he’s the victim of a political prosecution, inside the courtroom his lawyers will have to address the specific charges. They will win or lose based on legal arguments, not bluster.

“I’ve been around for 50 years, and I’ve heard the political argument before,” said Stanley M. Brand, a veteran Washington defense lawyer. Mr. Brand cited the “Abscam” bribery case of the 1970s, when the defendants accused President Jimmy Carter of orchestrating the bribery sting, or the investigation of Senator Robert G. Torricelli, which was also surrounded by charges of politics. “It’s never worked in a court of law.”

James Bopp Jr., a conservative defense lawyer, said he agreed with virtually all Republicans that the Manhattan district attorney had coaxed his grand jury to bring forward a specious indictment for the political purpose of damaging Mr. Trump.

But, he said, Mr. Trump’s lawyers must answer the charges, not grandstand on the politics.

“A charge is not automatically dismissible because it’s brought for political purpose,” he said. “The motive of prosecutors may be pertinent to the broader society. It’s not pertinent to a judge.”

The exact charges against Mr. Trump may not be known until he is arraigned on Tuesday. The grand jury that brought the indictment was examining payments to Stormy Daniels and the core question of whether those payments were illegally disguised as business expenditures, a misdemeanor that would rise to a felony if those payments could be labeled an illegal campaign expenditure.

If past legal skirmishes are an indication, Mr. Trump is likely to drag the proceedings out for months, if not years, with motion after motion as he builds his third presidential campaign around what he called on Friday the “unprecedented political persecution of the president and blatant interference in the 2024 election.”

Likewise, Fox News will almost certainly continue to frame the Dominion case as that of a corporation intent on stifling the First Amendment’s guarantees of free speech and freedom of the press.

“This case is and always has been about the First Amendment protections of the media’s absolute right to cover the news,” the network said in a statement Friday.

That may be left for a court to decide.

Ken Bensinger contributed reporting.