Is this a presidential election or a criminal case? Increasingly, it’s difficult to distinguish the difference.

The Washington Post reports that “prosecutors are nearing a decision on whether to charge President Biden’s son Hunter with tax- and gun-related violations.” The chairman of the House Oversight Committee, James Comer, says he has financial records showing at least nine members of the Biden family “were involved with or may have benefited from the family’s business dealings with foreign adversaries.” 

President Trump, meanwhile, faces at least four different criminal probes. The district attorney of New York County, Alvin Bragg, is prosecuting Mr. Trump for 34 counts of falsifying business records in connection with alleged hush-money payments. Then there are federal investigations into Mr. Trump’s handling of classified documents and into his alleged interference with the 2020 election and with the peaceful transfer of power.

Ever since the press, congressional investigators, and a special prosecutor hounded President Nixon from office over the Watergate scandal, American presidential politics has been characterized by a conviction that the other side isn’t merely misguided but criminally corrupt.

President Carter’s brother Billy had shady dealings with Libya. The Reagan administration had Iran-Contra. President Clinton and his associates had the Whitewater land deal and then the Monica Lewinsky scandal. As a presidential candidate, Hillary Clinton faced an FBI investigation into her handling of email while she was secretary of state. President Trump endured Robert Mueller’s investigation into Russian meddling in the 2016 election.

Whatever you make of any of the individual cases, the effect of them in totality is to erode public trust in our political institutions. The prosecutions also discourage otherwise well-qualified individuals from entering public service. A potential politician would be foolish to run for office without first fully financing a legal-defense fund.

The arguments in these sorts of cases are so thoroughly rehearsed at this point that they transcend the particulars. The defense side complains about the criminalization of policy differences, mentions Robert Jackson’s classic speech on the danger that prosecutors will “pick people he thinks he should get, rather than pick cases that need to be prosecuted,” and invokes Harvey Silverglate’s “Three Felonies a Day” and Justice Scalia’s warning about sapping the “boldness” of the president. The prosecution side goes on about character, and about how no one is above the rule of law, and how America is a government of laws not of men.

Is there any way to break out of this destructive, vengeful cycle? 

The Constitution provides some guidance. It gives the president the power to grant reprieves and pardons, except in cases of impeachment. President Ford’s pardon of Nixon was an example of what George Washington called, and endorsed, as “tenderness”  that today would probably be bitterly denounced as the political class protecting its own. Expansive presidential use of the pardon power would go a long way toward tamping down prosecutorial excesses.

By establishing a process for impeachment and a high bar for conviction — a two-thirds vote in the Senate — the Constitution also implies that as the primary legal process for going after a sitting president. 

Presidents themselves can preserve their powers by exercising their executive authority over the Department of Justice. That gets seen somehow as improper interference, but what’s really improper is an unelected justice department undermining an elected president’s ability to lead.

Remember that the presidency is different from the other branches. It is the only branch in which 100 percent of the powers are vested in a single individual, who, outside the narrow provisions of third section of the 25th Amendment, cannot recuse himself and ask someone to act in his stead. A president who makes the mistake of appointing an independent or special counsel is basically shirking his responsibilities and is to blame for the headaches that result.

There are less conventional possible fixes. Raising congressional and presidential pay, say, would lessen the temptations of corruption. Broader criminal justice reforms — repeal of “conspiracy” statutes, genuine parity between public defenders and prosecutors, tougher penalties for prosecutorial misconduct, a crackdown on overcharging, and constraints on plea-bargain deals for witnesses who flip and provide “cooperative” testimony — could also help.

There’s legitimate public interest in fully understanding what the Biden family’s foreign financial dealings were, if any, and in what pressure Mr. Trump applied during the transition. There’s also legitimate public interest, though, in making sure that our elections get decided by voters, not prosecutors. Character, honesty, foreign influence, and the rule of law are all real issues — but so are national security and economic growth. 

A presidential election attracts somewhere between 130 million and 160 million voters. They aren’t perfect, but they are pretty good at sorting things out. Any prosecutor who attempts to substitute his own judgment, or that of a dozen jurors, for the vast collective wisdom of the American electorate is flirting perilously with subverting the constitutional plan.