This sums up why there are hardly ever any criminal campaign finance convictions: no one can understand the law

The questionable legal case against John Edwards - The Washington Post:
"Criminal violations of federal campaign financing laws require proof that the conduct was committed “knowingly and willfully.”’ In the context of a regulatory scheme such as is involved here, these words of specific criminal intent require proof that the offender was aware of what the law required, and that he or she violated that law notwithstanding that knowledge, i.e. that the offender acted in conscious disregard of a known statutory duty or prohibition."
Do these payments amount to contributions to the Edwards campaign? The Justice Department says they do because “public revelation of the affair and pregnancy would destroy his candidacy.” But Mr. Edwards’ campaign lawyer says that, had anyone bothered to ask her advice at the time, she would not have considered the payments to constitute campaign contributions. Scott Thomas, a former Federal Election Commission chairman retained by the Edwards legal team, said that in his view, “these payments would not be considered to be either campaign contributions or campaign expenditures within the meaning of the campaign finance laws” and that, if the matter came before the FEC, it “would conclude that these payments did not constitute a violation of the law, even as a civil matter,” no less a criminal one.