Too many louts get away with being one. So it was intensely satisfying to learn that the U.S. government, in the form of the Justice Department, was focusing its considerable might on John Edwards.

The former senator, vice presidential and presidential candidate would be exposed in a court of law as a preening fraud and disloyal husband. With a six-count indictment charging that Edwards violated campaign-finance laws came the promise that vengeance would be Elizabeth Edwards' – and ours.

But when the trial opened Monday with the area around the federal court in Greensboro, N.C., resembling a state fair (without the prize cow or butter sculptures), the Edwards case looked more like political spectacle than political justice. It was cathartic in June to see him marched into a federal courthouse for arraignment, a mug shot and fingerprinting. It wasn't so cathartic – it felt like overkill – to see Edwards on Monday, his daughter Cate at his side, as the machinery of the judiciary began to turn against him.

Yes, Edwards wove a terrible web of deception into which he drew his staff and friends, including an elderly heiress. Even as he pounded his chest about the "two Americas," he really only cared about one American as he tried to cover up his affair with Rielle Hunter, a campaign videographer who told him he was "hot." When that affair produced a child, Edwards took to the TV studios of America to deny he was the father – until a paternity test showed he was.

For all of this, he did not lose custody of the children he had with his wife, as most cads do. Elizabeth's death, in 2010, prevented that. John is the only parent they have, and one of the sadder pictures of the trial is Cate standing beside him, looking like his late wife. We get only one father; what's she to do?

The prosecutor's case rests largely on the premise that Edwards' image as a devoted family man was at the center of his candidacy. Therefore, any money he used to sustain that image is a potential violation of laws that dictate how campaign contributions can be spent. One problem with this strategy is that those laws are barely adequate to police misuse of large sums by politicians running for office, much less politicians running around. Search the legislative history and you won't find Congress imagining such perfidy. What prosecutors will try to do is show that Edwards' real purpose was to keep his secret from voters, not from his wife, with money subject to disclosure and other laws.

Under any circumstances, Edwards needed money that his wife wouldn't notice to pay for a household for his mistress. He turned to friends who were also contributors – not to help his campaign but to help him hide his affair.

Among them was Edwards' finance chairman, Frederick Baron, who acknowledged in 2008 that he had helped Hunter financially. He is now dead. Bunny Mellon, who is now 101 and donated more than $700,000 to Edwards's 2008 presidential campaign, is so old that she isn't taking the stand (her attorney is appearing for her). If she did, she would just look foolish. Mellon's checks went for Hunter's expenses, although Mellon apparently thought they were going to Edwards so he could have all the $400 haircuts he wanted without ridicule.

All she asked for in return was that Edwards attend her daughter's funeral. Consistent with his character, he did not.

You could argue that the way Mellon sent her checks – hidden in boxes of candy – is evidence that she knew she was violating the law. Good luck bringing her to account, however, or proving that Baron gave money as a campaign contributor and not as a friend. Meanwhile Andrew Young, the young Edwards staff member in charge of arranging this whole financial extramarital affair, has repeatedly lied about his role. Is a jury going to believe him now?

It's tempting for a prosecutor to try to prove the novel theory that hush money to a mistress is a campaign expense, like phone banks or handbills. Winning a political corruption case can make a lawyer's career, and once a case gets started it tends to get a life of its own. Higher-ups may be reluctant to stop such prosecutions for fear of being accused of political interference.

Yet such prosecutions can hurt defendant and government alike. Last month a judicial inquiry concluded that the 2008 trial of Sen. Ted Stevens of Alaska was driven by ambitious prosecutors who hid exculpatory evidence – but the findings came too late for Stevens, who lost his bid for re-election and died in 2010.

Questioning the appropriateness of possibly sending Edwards to jail is not to say that he has suffered enough. It's clear, to me anyway, that he can never suffer enough. It's just that his crimes were so much greater than violations of campaign-finance law.

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