John Edwards’s trial for campaign finance violations begins Monday. Government prosecutors will build on their unusual theory from last year’s indictment—which charged that the Edwards campaign should have treated payments to the candidate’s mistress as official campaign expenses. Many election law experts criticized that idea as an unprecedented overreach, and in a sign of how this prosecution is scrambling the politics that came before it, the conservative National Review just published a spirited editorial defending Edwards against the charges.

The editorial bears down on a point that Edwards’s lawyers are sure to make at trial: show me the money.

“Because none of the money [for the mistress] went to the campaign,” National Review explains, “and none of the money went for campaign expenses—inasmuch as maintaining a mistress is not a campaign expense—it is difficult to see why this should be prosecuted as a campaign-finance violation.”

Prosecutors counter that Edwards’s desire to run as a “family” candidate made hiding the mistress an electoral necessity. The problem with that, as I wrote when the indictment was released, is that federal rules actually run in the opposite direction. They specifically prohibit the expensing of any costs that “would exist even in the absence of the candidacy” (according to the FEC).

In other words, if a candidate paid for a mistress’s hotel rooms out of campaign coffers, that would also seem to be a violation of campaign finance law. It’s usually a bad sign if the prosecution’s theory is that the defendant broke the law no matter what he did.

Important caveats remain, of course. Edwards’s personal behavior was despicable, a point National Review made with gusto in its editorial (“the Dorian Gray of the Democratic party,” “one of the most loathsome characters in American politics,” “a preening, moralizing fraud”). The trial has not begun yet, new facts could emerge and there may be other laws that were broken separate from the novel theory on campaign expenses. But this case is troubling regardless of one’s feelings about Edwards; it suggests just how distorted and downright broken the regulation of campaign spending is in this country. A widely reviled former candidate faces jail time for money spent on a mistress without campaign expenditures, but candidates and Super PACs can legally raise vast sums from parties with far more direct interests before government without limitation or, in many cases, disclosure requirements. Legislating public funding for all federal elections would cut down on money’s influence in politics a lot more than prosecuting personal payments as campaign contributions, but it would be a lot harder to do.