"Man is the only animal that blushes," wrote Mark Twain. "Or needs to."

Shame is the soft power of justice, a means of punishing, and even banishing, people guilty of sins if not exactly of crimes. But here we are, our pale and shameless age increasingly defined on the one side by a president addicted to outrage and allergic to apology, and on the other by the zero-tolerance absolutes of social activists and partisans of all kinds.

Neither extreme satisfies our instincts for either justice or mercy. So how do we sustain values in an era that seems to dilute them? It's worth asking each day that Democrat Ralph Northam remains in the Virginia governor's mansion, Rep. Steve King, R-Iowa, plans his next campaign after being stripped of committee assignments, and Rep. Ilhan Omar, D-Minn., defends her positions on Israel even as Democrats melt down over how to condemn her for how she expresses them. We can agree that racism and sexism and anti-Semitism are to be condemned. But then what?

Of all the values he has twisted and drained, President Donald Trump has, by his brazen example, sapped the power of shame. Throughout 2016, he said things about women, Mexicans and Muslims that his critics considered disqualifying for the leader of a major party, much less the "Leader of the Free World." Yet enough voters in enough states decided they didn't want to be told which values matter most. Ever since, a loyal body of voters has stood by him; his most recent approval rating roughly matches that of Barack Obama and Bill Clinton at this stage of their presidencies.

Trump's continued success is clearly changing the math for others who come under fire. Northam, pilloried for days after his yearbook blackface photograph circulated, chose to gut it out, through a mangled apology, a walk-back ("that is not my picture"), then a disappearance from public view. He refused to heed demands from across his party to resign on the grounds that he could no longer govern effectively, as did King. Omar and her allies dismiss her offenses as the collateral damage of diversity and free speech. If professional survival is the ultimate value, those decisions may become the new standard for public figures under fire.

Here's the calculus: a supersonic news cycle and an attention supermagnet in the White House mean that if you can withstand the pain and humiliation of the initial firestorm, chances are the heat will subside and the crowd will move on. As politics grow ever more tribal, charges get filed away as mere partisan attacks. And the dynamic is self-reinforcing: Once one side abandons a character test, the other side is tempted to follow, leveling the political battlefield by lowering everyone's expectations.

While Twitter crackles with indignation, it falls to voters to weigh the evidence: Did the offense occur 30 years ago or this morning? Was it an error or a pattern? Does the accused take responsibility, demonstrate a capacity for change? King was hardly unreasonable to announce his re-election plans, because his long history of race baiting has yet to sink him with Iowa voters. Northam at least nodded in the direction of penitence; while weaseling about the authenticity of the yearbook photo, the governor promised to address his "white privilege" while setting out on a vague "reconciliation" tour. With the advantage of term limits, he has three more years to convince voters they were right to stand by him, without facing the final verdict of the ballot box.

Saying a politician should resign because he or she can no longer be effective seems more like a rush to judgment than actual justice. Sen. Kirsten Gillibrand, D-N.Y., acknowledges that she will pay a price with some in her party for her fierce prosecution of Al Franken, who was driven to resign from the Senate over charges of sexual misconduct without a complete Ethics Committee investigation and despite a solid feminist voting record. Even some victims of his alleged misconduct wanted him to remain in office, and as he left, he noted, "I, of all people, am aware that there is some irony in the fact that I am leaving, while a man who has bragged on tape about his history of sexual assault sits in the Oval Office."

Zero tolerance leaves little room for learning. Worse, it denies voters the right to reckon with their own judgments and misjudgments about the candidates they elect. The very definition of democracy is to trust voters to act as jurors; they don't take well to having their privileges revoked, either by media mobs or political partisans. You can criticize, you can condemn, but in our age of mass acceleration, demanding resignations is less and less likely to work, and that may be a good thing. If you find Omar's views abhorrent, or King's, or Trump's, the trial date has been scheduled: Nov. 3, 2020. There's plenty of time for discovery and oral arguments. And then for justice, as defined by those with the most at stake: we the people.

Nancy Gibbs is the visiting Edward R. Murrow professor of press, politics and public policy at Harvard University. She wrote this for the Washington Post.