Let’s imagine that President Donald Trump gave a White House news conference in the nude. “As you can see,” he might say, paraphrasing the semi-apocryphal quip Winston Churchill made when FDR accidentally encountered him emerging from a hot bath in the White House, disrobed, “I have nothing to hide from the American people.”

In the District of Columbia, public indecency of this sort is a misdemeanor punishable by a fine of $500 and up to 90 days in jail. Yet few people would immediately defend the president’s behavior as nothing more than a minor legal faux pas. (Save, perhaps, the vice president, who might applaud such presidential transparency.)

This kind of violation of norms and decency would have the Cabinet scrambling to invoke the 25th Amendment. Even the Republican House Freedom Caucus would talk openly about impeachment because the public would have lost faith and confidence in the president almost as quickly as it would if he had stood in the middle of Fifth Avenue and shot someone.

Meanwhile, in the real world, the president stands credibly accused of violating far more serious laws than misdemeanor public indecency. In filings this month, the U.S. attorney for the Southern District of New York told a judge that the president abetted campaign finance violations — felonies that come with a maximum prison sentence of five years.

But the reaction to these accusations, from both his defenders and his critics, is a fog of legalisms. The only difference between the two sides is whether or not the alleged illegalities are grave or trivial.

The real issue should be whether or not the president has violated the public trust, a concept that covers far more than squabbling between lawyers.

In Alexander Solzhenitsyn’s legendary 1978 commencement address at Harvard, he lamented how in the West, law had replaced higher notions of morality.

“Any conflict is solved according to the letter of the law and this is considered to be the supreme solution,” he observed. “If one is right from a legal point of view, nothing more is required. Nobody will mention that one could still not be entirely right, and urge self-restraint, a willingness to renounce such legal rights, sacrifice and selfless risk. It would sound simply absurd.”

This is a point that conservatives once understood. Here is Franklin Graham, the son of Billy Graham, writing about Bill Clinton in The Wall Street Journal in 1998: “If he will lie to or mislead his wife and daughter, those with whom he is most intimate, what will prevent him from doing the same to the American public?”

Mr. Graham added: “The private acts of any person are never done in secret. God sees and judges all sin, and while He seeks to restore the offender with love and grace, He does not necessarily remove all the consequences of our sin.”

In May, when weighing in on the allegations of infidelity against Mr. Trump, Mr. Graham completely reversed his stance on the topic of private versus public behavior. “That’s for him and his wife to deal with,” he told the Associated Press. “And I think this thing with Stormy Daniels and so forth is nobody’s business.”

The point here isn’t hypocrisy, though there’s plenty of that going around. Before the Monica Lewinsky scandal, Mr. Clinton’s defenders considered his past sexual behavior “old news.” After the revelations, they insisted that perjury about sex was no big deal. Now, many of those same people are arguing that illegal cover-ups of affairs are grounds for impeachment.

It’s not quite an apples-to-apples comparison, but that’s irrelevant. The point is that we’ve lost the ability to speak clearly across partisan lines about basic notions of decency and morality.

The debate over impeachment highlights the problem. A president can be impeached for any reason Congress sees fit. It’s a political tool for sanctioning a president who violates the public trust. The rules of criminal procedure are only relevant, if at all, procedurally. Instead, they are used as a substitute for moral or civic judgment.

I am not arguing for impeaching Mr. Trump based on what we know now. The precedent of Mr. Clinton’s impeachment (but acquittal in the Senate) demonstrates, among other things, that politically you need more than this for a binding national consensus.

I am arguing that we’ve lost anything remotely like a moral consensus in this country because legalism has crowded out morality. That’s the naked truth.

Jonah Goldberg is a fellow at the American Enterprise Institute and a senior editor of National Review. His latest book is “The Suicide of the West.” Email: goldbergcolumn@gmail.com; Twitter: @JonahNRO.