Donald Trump, who has often lied, unquestionably told the truth when he said Thursday was a "dark day" for America.

The ex-president's social media post correctly described the magnitude of his indictment over the alleged mishandling of classified documents -- though completely ignored any personal culpability in the case.

But the first-ever indictment of a former president by a federal grand jury thrust the country into an unprecedented and perilous moment in its history at a time when it is already internally estranged over politics.

Criminal probes of former presidents and current presidential candidates might be business as usual in tottering developing world states. But there's no parallel for an ex-commander in chief facing federal charges in the US, much less one who has already incited violence in order to advance his political ends and is currently running to recapture the White House.

America's legal and political institutions, which were repeatedly torn apart by Trump's tumultuous term in office, may now face their biggest test from an ex-president who was impeached twice, tried to steal an election and is already facing a separate criminal trial next March.

If that was not serious enough, these federal charges -- related to classified documents that Trump took to his Mar-a-Lago resort -- are coming down at a moment when Trump is the front-runner for the Republican nomination in 2024.

These seven counts bring a host of political complications, even if the Justice Department will argue that it's simply following the evidence and is proving that no one, not even former presidents, are above the law.

Simply put, Trump is set to be brought to trial by the Justice Department of his successor. In another profound twist, that successor -- President Joe Biden -- could end up facing the accused in the 2024 general election, in a scenario that would inject new fervor into Trump's claims he's a victim of politicized justice. Trump's supporters already thought that an invisible "deep state" establishment was out to get their hero. It will be even worse now.

Trump, who has been preparing the ground for a possible federal indictment for months, and who has been hugely successful in convincing his supporters that any scrutiny of his life, political decisions or business affairs adds up to politicization, wasted no time making that case.

"I am an innocent man. I did nothing wrong," the former president said in a video that showed that he is willing to torch America's democratic electoral system if that is what it takes to clear his name.

"It's called election interference. They're trying to destroy your reputation so they can win an election. That's just as bad as doing any of the other things that have been done over the last number of years," said Trump, who is due to appear in court in Miami on Tuesday for an arraignment.

Why the new indictment could be more serious than the first

Amazingly, this was not the first time Trump was indicted. He already became the first ex-president to be charged with a criminal offense when a Manhattan grand jury indicted him. He faces more than 30 counts related to business fraud in a case arising from a hush money payment in 2016 to adult film actress Stormy Daniels. The case is due to go to trial next March -- right in the middle of primary season. Trump has pleaded not guilty.

But the indictment by the special counsel in the documents case is a far graver affair and more politically sensitive since it comes from Biden's Justice Department.

Trump is facing a charge under the Espionage Act, his attorney Jim Trusty said on CNN Thursday, as well as charges of obstruction of justice, destruction or falsification of records, conspiracy and false statements.

While all the exact charges against Trump were not immediately clear, the potential offenses strike at the core of some of the most somber duties of the presidency -- including the protection of the country's most vital secrets. And any allegation of obstruction involves another fundamental role of the public trust that Trump held and to which he aspires in the current campaign -- the obligation of a president to uphold the laws.

The current scenario will test whether the US remains a nation of laws. If evidence exists that Trump has indeed committed alleged breaches of the criminal code, a decision not to charge him would shatter the principle that everyone is equal under the law. But some will ask whether the indictment is truly in the national interest given the backlash against democratic and judicial institutions certain to be whipped up by the ex-president.

Thursday evening's news sparked a firm push back from some Republicans eager to prove their loyalty to Trump.

"Today is indeed a dark day for the United States of America," House Speaker Kevin McCarthy said in a tweet. "I, and every American who believes in the rule of law, stand with President Trump against this grave injustice."

New York Rep. Elise Stefanik, a member of the House GOP leadership, parroted Trump's political argument, tweeting: "The radical Far Left will stop at nothing to interfere with the 2024 election in order to prop up the catastrophic presidency and desperate campaign of Joe Biden."

And GOP Sen. Josh Hawley of Missouri tweeted: "If people in power can jail their political opponents at will, we don't have a republic." His comments ignore the fact that the ex-president is entitled to defend himself in a court of law.

While outsiders cannot know the full breadth of special counsel Jack Smith's investigation, reports in recent days had suggested an aggressive probe nearing its conclusion.

— CNN reported at the end of May that prosecutors had obtained an audio recording in which Trump acknowledged he held onto a classified Pentagon document about a potential attack on Iran. This undercut his arguments that he declassified everything he took from the White House.

"It obliterates many of the defenses that he has launched over the last few months," Former FBI Deputy Director Andrew McCabe said of the tape on CNN on May 31. "It conclusively establishes not only that he took classified information, because he admits that, but also that he knew he had classified information. He admits that as well, and that he knew it was still classified, and he was limited in how he could handle it or distribute it."

— In another development, CNN exclusively reported this week that an employee at Mar-a-Lago drained the resort's swimming pool last October and ended up flooding a room where computer servers containing surveillance video logs were kept. The incident happened roughly two months after the FBI retrieved hundreds of classified documents from the residence and as prosecutors probing possible obstruction obtained surveillance footage to track how White House records were moved around the resort. It is unclear whether the room was flooded intentionally or by mistake, but the incident occurred amid a series of events that federal prosecutors found suspicious.

— It is now known that the special counsel has been using two grand juries, one in Washington, DC, and the other in Miami, which could mean Smith is exploring whether to bring parts or all of a criminal case in Florida federal court instead of in the nation's capital.

— In another revelation that thickened mystery around the case and may have deepened Trump's potential exposure, the New York Times first reported this week that Mark Meadows, the former White House chief of staff, testified to a grand jury that asked him about both Trump's handling of classified documents and attempts to overturn the 2020 election -- efforts that Smith is also investigating.

— On Thursday, CNN's Zachary Cohen revealed that a key former White House official who worked in both the Trump and Obama administrations was interviewed by special counsel prosecutors earlier this year. The official said that he told prosecutors that Trump knew the proper process for declassifying documents and followed it correctly at times while in office. This information could undercut Trump's claims that he thought he could simply declassify material on a whim and also gets to the issue of his intent -- an important question in a criminal case.

The political reverberations from the documents case

None of these glimpses into Smith's investigation are unfolding in a vacuum. The Republican primary field is getting more crowded by the day, but Trump's rivals are struggling to create rationales for their candidacies in a party still in thrall to him. Trump's legal problems, however, are unspooling amid huge uncertainty about how multiple indictments could limit his capacity to campaign and whether they could cause some Republican voters to take a deeper look into his vulnerabilities in a general election.

With a trial date set for March in the Manhattan case, Trump is also expected to hear by the end of the summer whether he or subordinates will be charged in a separate case in Georgia related to his attempt to overturn Biden's 2020 win there.

In a sign of the way that Trump will attempt to have this case tried in the court of public opinion before it ever reaches the courts, his campaign immediately sent around fundraising emails that touted the hauls it brought in after he was indicted in Manhattan.

Early evidence in polling after that first indictment suggested that if anything Trump may have benefited politically from Manhattan District Attorney Alvin Bragg's move. Those charges effectively forced his primary rivals to defend him in order to avoid alienating GOP voters, thus defanging one of their potential attacks on an ex-president who has constantly tested the rule of law.

Florida Gov. Ron DeSantis responded similarly Thursday night by adopting Trump's "weaponization" language. "The weaponization of federal law enforcement represents a mortal threat to a free society," he tweeted before making his own White House pitch. "The DeSantis administration will bring accountability to the DOJ, excise political bias and end weaponization once and for all."

And in a CNN town hall on Wednesday night, former Vice President Mike Pence -- who just announced his own White House bid -- warned that "no one is above the law" while also calling on the Justice Department not to indict his former boss, saying such a move would "send a terrible message to the wider world." His position was logically contradictory, but politically comprehensible given the dynamics in the Republican Party.

While Trump has managed to leverage his legal exposure so far in the campaign, it is not a given that it will hold at this early stage. The issue of electability could become more of an issue next year given that Trump's dramas have alienated swing voters in a way that's hurt the GOP in recent elections.

And as the scheduling of Trump's trial in Manhattan next spring shows, defendants finds that their calendars soon become filled with court dates, hearings and other commitments. This could become a serious issue for the former president if he's facing multiple days in court next year.

At the same time, however, the constitutional and judicial system that he has often decried would ensure he would be entitled to the same presumption of innocence as anyone else and will have the right to mount a robust defense.