Call it Paul Ryan’s finest hour. It’s a video of the congressman from Wisconsin confronting the Commissioner of Internal Revenue over the missing Lois Lerner emails. It’s easy to see why the clip is going viral on the Web. It is one of those rare moments when Congress loses its temper and a major figure says what the American people are thinking. They don’t believe Commissioner John Koskinen is telling the truth. They don’t believe him. Mr. Koskinen protested. No one believed that either.

Mr. Ryan’s ire was triggered by the suggestion of one of the Democrats that Mr. Koskinen was owed an apology for the tough grilling he was receiving from the committee. “The apology that ought to be given,” Mr. Ryan responded, “is to the American taxpayer.” Then he said: “Sitting here listening to this testimony, I don’t believe it.” He paused. “That’s your problem,” he said with a nod to the commissioner. “Nobody believes you.”

Mr. Ryan then reviews the failure of the IRS to be forthcoming — its burying of bad news in its communications with Congress, its tardiness in responding to requests for information — culminating in the discovery that not only are key Lerner emails are missing but that the hard drive has not only crashed, but has been destroyed, and that six other hard drives are involved. With each syllable, Mr. Koskinen seems to miss the essential point.

“You are the Internal Revenues Service,” Mr. Paul says. “You can reach into the lives of hardworking taxpayers. And with a phone call, an email or letter you can turn their lives upside town. You ask taxpayers to hang onto seven years of their personal tax information in case they are ever audited, and you can’t keep six months of employee emails.”

At one point the commissioner said “I have a long career, that’s the first time someone has said they do not believe me.” He seems oblivious to what is happening. The House of Representatives may be in the hands of the Republicans. But it is a house of Congress. It senses both dishonesty and arrogance on the part of the tax arm of the government. We don’t have votes of confidence under the American system. But the IRS has lost it, a fact that is animating a scandal that goes to the heart of the democratic process and is likely to consume much of the rest of the Mr. Obama’s presidency.