Attorney General Kathleen Kane made a sound response to one of her key critics recently when she challenged Philadelphia District Attorney Seth Williams to take up a convoluted corruption case that she had decided not to pursue.

Mr. Williams had sharply criticized Ms. Kane for her assertion that the case, which she had inherited, was not prosecutable due to poor evidence, potential entrapment, possible racial targeting and a highly unsympathetic figure of an informant whose alleged crimes were worse than those of the investigation's targets.

Last week, Ms. Kane told Mr. Williams, in effect, that if he wanted the case, it was all his. But don't expect a prosecution, for precisely the reasons that Ms. Kane had cited in the first place.

Dauphin County Judge Todd Hoover last week unsealed about 1,000 pages of documents relevant to the case, at the request of news organizations. Although the judge was not pleased with Ms. Kane's supporting petition, the case history demonstrates why she was right to drop the case.

Tyron Ali, a sort-of lobbyist who had been charged with 2,088 counts of fraud for allegedly stealing more than $430,000 in public funds intended for nutrition programs for poor children and seniors, was "flipped" to become an informant.

But his targets, as many as seven African-American Democratic state representatives from Philadelphia, had not been suspected of any crimes until Mr. Ali created ones. He contends that they accepted the cash. But to be prosecutable bribes, the transactions required a quid pro quo.

But in this case, the supposed quid pro quo was laughable - opposition to the Voter ID Law. Since that law was designed to suppress Democratic votes, especially those of many of the targets' constituents, the notion that the representatives were enticed to vote against it is nonsense. Every Democratic state representative voted against the bill as a matter of policy.

No wonder Ms. Kane's predecessors allowed the case to lay idle for 18 months. And when they entered an agreement with Mr. Ali to drop all 2,088 charges against him before he testified - after Ms. Kane was elected and before she took office - the case effectively was dead.

The case isn't over. At a minimum, the representatives face an ethics inquiry. But the question of whether Ms. Kane should have walked away from this dog's breakfast should be settled in her favor.