The John Edwards Mistrial: What Went Wrong The former presidential candidate was proved to be a heartless husband and a terrible boss but not a criminal Sara D. Davis/Getty Images Former U.S. Sen. John Edwards addresses the media alongside his daughter Cate Edwards and his parents Wallace and Bobbie Edwards at federal court May 31, 2012 in Greensboro, North Carolina Cohen is the author of Nothing to Fear: FDR's Inner Circle and the Hundred Days that Created Modern America The gap between being a bad person and being a criminal is often wide. That simple fact is what allowed John Edwards to beat the charges against him. Prosecutors offered a great deal of evidence that confirmed what many people already believed: that Edwards has serious character flaws and treated people close to him terribly. What they did not do was prove that he had committed a crime. In its verdict on May 31, the jury acquitted Edwards of only one of the six counts against him, involving $725,000 given by heiress Rachel "Bunny" Mellon that was used to support his mistress. Specifically, prosecutors failed to prove that Edwards knew that the money was a campaign donation and not a "gift." (In order to hide the payments from her financial planners, Mellon wrote the checks to her decorator, Bryan Huffman, who then endorsed them over to Edwards aide Andrew Young. Mellon, now 101, has poor hearing and eyesight and was not called to testify.) But a Justice Department source has told the Associated Press that the government is highly unlikely to prosecute Edwards again on the five deadlocked charges. In other words: Edwards appears to be free and clear. MORE: John Edwards Case Ends in Mistrial as Jury Deadlocks The victory of the former North Carolina Senator and onetime presidential candidate was in part due to a shrewd tactical decision by the defense: it played up the bad person/criminal distinction brilliantly. Edwards never tried to clear his name. Even in his postverdict remarks, he declared: "While I do not believe I did anything illegal, or ever thought that what I was doing was illegal, I did an awful, awful lot that was wrong." In case there was any doubt, he referred to his "sins," which he insisted that he alone was responsible for. This approach played into the fundamental weakness of the prosecution's case. The one thing prosecutors did well at the trial was prove what Edwards freely admits: that "awful, awful lot that was wrong" part. Witnesses painted a vivid portrait of Edwards" infidelity, which had him cheating on his much admired wife Elizabeth while she was battling terminal cancer. The adultery was well known, but the trial brought out cringe-worthy new details, such as Elizabeth's tearing off her blouse and curling up in a ball in an airport parking lot after a tabloid printed an article about it. If the trial showed Edwards to be a heartless husband, he came off no better as a father. It underscored that he had originally denied paternity of the child he fathered with his mistress, Rielle Hunter. The trial also provided a reminder of the impact the affair had on his older children when his daughter Cate at one point left the courtroom crying. There were plenty more moments that put Edwards in an awful light, including his allegedly persuading his close aide, Andrew Young - himself married and a father - to claim that he was the father of Hunter's child. MORE: Kerry's Regrets about John Edwards While the government presented a convincing case for Edwards" general turpitude, what it failed to do was show that he had committed a crime. This prosecution was a stretch from the beginning. Edwards was accused of violating campaign-finance laws, but those laws are notoriously arcane. None directly addresses a candidate's or his staff's soliciting contributions to cover up a candidate's affair. It was not surprising that, navigating this murky legal landscape, at least some jurors would accept the defense's contention that the funds were gifts rather than campaign contributions - and that the campaign-finance laws therefore did not apply. Even before the trial began, there was criticism of the prosecutors, and it has ramped up considerably since the verdict. The Justice Department's public-integrity section, which spearheaded the case, had its reputation badly tarnished a few years back when it bungled a case against Alaska Senator Ted Stevens, whose conviction was overturned because of prosecutorial missteps. And earlier this year, a major corruption case it brought in Alabama fell apart. The mistake the Justice Department made in the Edwards prosecution was not in how it tried this case but in bringing it at all. In recent years, funds have poured into campaigns at an unprecedented rate - and much more is being spent by shadowy PACs and super PACs. But few cases have been brought against these big-money folks, and none that grabbed anything like the headlines the Edwards case did. Any juror who has been paying attention no doubt began the trial by wondering why, with everything that is wrong with politics today, the government was so intent on punishing the cover-up of a marital affair. The Edwards prosecution was not just small potatoes - it was unnecessary. Edwards" offense was not violating campaign-finance law. He was guilty of leading his life in a reprehensible way. And for that he has already been convicted in the proper tribunal: the court of public opinion. MORE: Inside the Presidents Club Cohen, the author of Nothing to Fear, teaches at Yale Law School. The views expressed are solely his own.