For the first time in American history, a grand jury has indicted a former president of the United States, The Times reported on Thursday. Donald Trump spent years as a candidate, in office and out of office, ignoring democratic and legal norms and precedents, trying to bend the Justice Department and the judiciary to his whims and behaving as if rules didn’t apply to him.

As the news of the indictment shows, they do.

A pattern of disregard for the law often leads to a criminal indictment, and that is the outcome Mr. Trump now faces. Federal and state prosecutors were right to set aside concerns about political fallout, or reverence for the presidency, and initiate thorough criminal investigations of Mr. Trump’s conduct in at least four instances. The investigation by the Manhattan district attorney is the first known to result in an indictment.

Mr. Trump completely transformed the relationship between the presidency and the rule of law, often asserting that a president was above the law. So it is appropriate that his actions as president and as a candidate should now be formally weighed by judges and juries, with the possibility of criminal penalties on the line. Mr. Trump badly damaged America’s political and legal institutions and threatened them again with calls for widespread protests once he is indicted. But those institutions have proved to be strong enough to hold him accountable for that harm.

A healthy respect for the legal system also requires Americans to set aside their politics when forming judgments on these cases. While Mr. Trump routinely called for his enemies to be investigated by the F.B.I., to be indicted or to face the death penalty, his indifference to due process for others shouldn’t deny him the system’s benefits, including a fair trial and the presumption of innocence. At the same time, no jury should extend to him any special privileges as a former president. He should have to follow the same procedures as any other citizen.

The indictment remains sealed, and the exact charges against Mr. Trump may not be known for several days. But Alvin Bragg, the district attorney, has been pursuing a case of possible fraud and campaign finance violations by Mr. Trump for concealing payments he made to the porn-film star Stormy Daniels before the 2016 election. His actions — using money to silence critics and hide politically damaging information — were wrong. The question that will face a jury is whether that behavior meets the threshold for conviction as a felony.

If those are the charges, conviction will hinge on proving that Mr. Trump participated in falsifying business records while violating campaign finance law, a somewhat novel legal strategy. Falsifying records can be charged as a misdemeanor in New York; to make it a more serious felony requires proof that he combined it with a second crime, in this case, a potential campaign finance violation. The former president, who is seeking a second term in 2024, has denied the allegations and has said that the case against him brought by Mr. Bragg, a Democrat, is politically motivated.

While some legal experts have questioned the theory behind Mr. Bragg’s case, there is no basis for the accusation that it is politically motivated — a claim that Mr. Trump has made, for many years, about every investigation into his conduct. Just as jurors are routinely instructed to ignore evidence that is improperly introduced in a trial, they will also have to ignore the unsubstantiated implications raised by Trump supporters and attorneys in these cases and judge them strictly on the merits.

Three of the other investigations that may result in indictments are more serious, because they involve allegations not just that Mr. Trump violated the law but also that he abused his presidential office.

Among the most egregious are the accusations against him in Georgia. The Fulton County district attorney, Fani Willis, is weighing criminal charges against several people, including Mr. Trump, for attempting to overturn the results of the 2020 presidential election in that state, which President Biden won by 11,779 votes. Mr. Trump repeatedly pressured Georgia’s secretary of state, Brad Raffensperger, to “find” additional votes that would change the results of the state’s election, part of a scheme to undermine the will of the voters.

A special grand jury impaneled by Ms. Willis recommended in February that charges be brought in the case; it’s not yet known which people or allegations were included in the grand jury’s recommendations or whom, if anyone, Ms. Willis may seek to indict.

A federal Justice Department inquiry led by a special counsel, Jack Smith, could also result in charges against Mr. Trump. Mr. Smith is investigating the former president’s efforts to prevent the peaceful transfer of power on Jan. 6, 2021, when Mr. Trump roused an armed mob that attacked the U.S. Capitol, threatening lawmakers who were gathered to certify the results of the presidential election. A bipartisan Senate report last year found that seven deaths were related to the attack.

Mr. Smith’s team is also investigating the former president over his mishandling of classified documents that were removed from the White House and taken to Mar-a-Lago, his private residence in Florida. Some 300 classified documents have been recovered in the case. Prosecutors are also examining whether Mr. Trump, his attorneys or staff members misled government officials seeking the return of the documents.

In addition to criminal charges, Mr. Trump faces several civil lawsuits. New York’s attorney general, Letitia James, is suing the former president for “grossly” and fraudulently inflating the value of his real estate assets. Three of Mr. Trump’s adult children are named in the suit as well. A group of Capitol Police officers and Democratic legislators are suing the former president, arguing that his actions on Jan. 6 incited the mob that caused them physical and emotional harm. E. Jean Carroll, a writer who accused Mr. Trump of raping her, is suing the former president for defamation. Mr. Trump denies the charges.

Prosecuting the former president will no doubt widen the existing political divisions that have so damaged the country in recent years. Mr. Trump has already stoked that divisiveness, calling prosecutors behind the probes — several of whom are Black — “racist.” He claimed in a social media post that he would be arrested and called on his supporters to “PROTEST, TAKE OUR NATION BACK!” The language echoed his rallying cry that preceded the Capitol riot. Officials in New York City, taking no chances on a repeat performance by Mr. Trump’s supporters, have been preparing for unrest.

Those accusations are clearly aimed at undermining the allegations against him, inoculating himself from the consequences of his misconduct and using the cases to his political advantage. The two district attorneys in these cases are elected Democrats, but their race and political affiliations are not relevant to the legal proceedings. (Mr. Smith is not registered with either party.) Nevertheless, House Speaker Kevin McCarthy immediately demonstrated his party’s intent to politicize the indictment by calling Mr. Bragg “a radical DA” pursuing “political vengeance” against Mr. Trump. Mr. McCarthy has no jurisdiction over the Manhattan district attorney and no business interfering in a criminal prosecution, and yet he vowed to have the House of Representatives determine whether Mr. Bragg’s office is receiving federal funds.

The decision to prosecute a former president is a solemn task, particularly given the deep national fissures that Mr. Trump will inevitably exacerbate as the 2024 campaign grows closer. But the cost of failing to seek justice against a leader who may have committed these crimes would be higher still.