Trump humor? I never had sexual relations...
Nothing to do with the case. The Cohen plea is a sweetheart deal. Just like when enviro activists sue the EPA to force them to do exactly what the EPA wanted to do in the first place. The case goes to court, and the EPA puts up a nominal objection but actually wants to lose the case.In this case Mueller wants Trump to look bad, so he puts the squeeze on Cohen - then tells him hell get off easy if he plead guilty to a violation of a law which implies that President Trump was in cahoots with Cohen in that violation.
Cohen, in this case, acts as if hes the worst lawyer in the world (just as in the EPA example), pleading guilty to what is actually legal (if immoral, but after Slick Willie whos counting?) behavior.
Cohen is cooperating in a Mueller double overstretch of the law: first, not every expense a candidate undertakes during a campaign is reportable as a campaign expense. The case would have to be made that Trump would not have done that if he hadnt been running for POTUS in order for it to be such - a case that an awful lot of politicians would scream bloody murder if they were held to that standard (e.g., a congressional slush fund, paid by taxpayers, for exactly the same purpose is a lot worse than that).
If a Democrat - e.g., Barak Hussein Obama - does get caught in not reporting campaign funds correctly, its a spitting on the sidewalk offense. With Trump, there are cries for impeachment when the very people talking would probably be ensnared by the same law.
. . . which gets us to the nub of the issue: Campaign Finance Reform is unconstitutional. Nobody regulates the newspapers because of the First Amendment. And the newspapers can therefore buy ink by the carload and use it to promote whatever political campaigns they want. No campaign finance reporting requirement for them. The planted axiom of CFR is that the media arent biased. But being a journalist is not being a priest in a government-established religion (which 1A also forbids).
To give you an idea of how firm the footing of CFR is, McConnell v. FEC - which validated McCain-Feingold against a SCOTUS challenge - was a 5-4 decision (Sandra Day OConnor deciding vote).