Among the attributes I most envy in a public man (or woman) is the ability to lie. If that ability is coupled with no sense of humor, you have the sort of man who can be a successful football coach, a CEO or, when you come right down to it, a presidential candidate. Such a man is Mitt Romney.

Time and time again, Romney has been called a liar during this campaign. (The various fact-checking organizations have had to work overtime on him alone.) A significant moment, sure to surface in the general election campaign, came during a debate held in New Hampshire in January. David Gregory, the host of “Meet the Press,” turned to Newt Gingrich and said, “You have agreed with the characterization that Governor Romney is a liar. Look at him now. Do you stand by that claim?”

Gingrich did not flinch. “Sure, governor,” he started off, and then accused Romney of running ads that were not true and, moreover, pretending he knew nothing about them. “It is your millionaire friends giving to the PAC. And you know some of the ads aren’t true. Just say that straightforward.”

Me, I would have confessed and begged for forgiveness. Not Romney, though — and herein is the reason he will be such a formidable general-election candidate. He concedes nothing. He had seen none of the ads, he said. They were done by others, he added. Of course, they are his supporters, but he had no control over them. All this time he was saying this rubbish, he seemed calm, sincere — matter of fact.

And then he brought up an ad he said he did see. It was about Gingrich’s heretical support for a climate-change bill. He dropped the name of the extremely evil Nancy Pelosi. He accused Gingrich of criticizing Paul Ryan’s first budget plan, an Ayn Randish document whose great virtue is a terrible honesty. (We are indeed going broke.) He added that Gingrich had been in ethics trouble in the House and ended with a promise to make sure his ads were as truthful as could be. Pow! Pow! Pow! Gingrich was on the canvas.

I watched, impressed. I admire a smooth liar, and Romney is among the best. His technique is to explain — that bit about not knowing what was in the ads — and then counterattack. He maintains the bulletproof demeanor of a man who is barely suffering fools, in this case Gingrich. His message is not so much what he says, but what he is: You cannot touch me. I have the organization and the money. Especially the money. (Even the hair.) You’re a loser.

There are those who maintain that President Obama, too, is a liar. The president’s recent attack on Ryan’s new budget proposal sent countless critics scurrying to their thesauruses for ways to say lie — “comprehensively misrepresenting” is the way George F. Will put it. (He also said Obama “is not nearly as well educated as many thought.”) Obama does indeed sometimes play politics with the truth, as when he declared that a Supreme Court reversal of his health care law would be unprecedented. He then backed down. Not what he meant, he said.

But where Romney is different is that he is not honest about himself. He could, as he did just recently, stand before the National Rifle Association as if he were, in spirit as well as membership, one of them. In body language, in the blinking of the eyes, in the nonexistent pounding pulse, there was not the tiniest suggestion that here was a man who just as confidently once embodied the anti-gun ethic of Massachusetts, the distant land he once governed. Instead, he tore into Obama for the (nonexistent) threat the president posed to Second Amendment rights — a false accusation from a false champion.

A marathon of debates and an eon of campaigning have toughened and honed Romney. He commands the heights of great assurance, and he knows, as some of us learn too late in life, that the truth is not always a moral obligation but sometimes merely what works. He often cites his business background as commending him for the presidency. That’s his forgivable absurdity. Instead, what his career has given him is the businessman’s concept of self — that what he does is not who he is. This is what enables the slumlord to be a charitable man. This is what enables the corporate raider to endow his university. Business is business. It’s what you do. It is not who you are. Lying isn’t a sin. It’s a business plan.

cohenr@washpost.com