(sigh)
1. If we are talking about the Stormy Daniels non-disclosure agreement, so far what we know is that Cohen and Trump discussed the process, Cohen advanced a payment and was then repaid by Trump. The argument seems to be that this was a campaign expense, trying to hide something that might prove a negative if used as campaign dirt against Trump. That it was a loan in excess of allowable contributions for such expense.
2. Arguing for the case, then the person who violated the law was Cohen, who "contributed" his own money in excess of the limits. However, as Trump paid him back, the argument is that he accepted the excessive loan amount even temporarily, in violation of campaign finance rules. At WORST he would face a fine. (Recall, Obama failed to properly report over $2 million in donations and was fined $375,000. No one mentioned charges).
https://www.politico.com/story/2013/01/obama-2008-campaign-fined-375000-085784
3. However, arguing against the case? Records should show that Cohen acting for Trump had processed several non-disclosure agreements over the course of his representation. This was during the years prior to the campaign. This would show that his recent actions were in keeping with his past efforts in legal representation, and NOT a special "campaign" activity. If that is the case then the "temporary loan" in expectation of being repaid was NOT a campaign expense but rather a legal expense billable to the client. Thus when Trump reimbursed his attorney for legal fees and costs, this process resulted in use his own money. So even if someone (Cohen for example) tried to tie this to the campaign, there is no limitation on the use of personal money for campaign expenses.
IMO this is just more TDS efforts to smear the President. Any and every possibility of mud throwing.
I'd say if this is pushed it is a weak case at best. Trump may end up being fined. Or the entire issue may be dismissed as a non-issue.