Close to the 2016 election, the "Access Hollywood" tapes featuring Donald Trump resurfaced and Trump was having major problems with women voters. Trump and his campaign realized they had to muzzle Stormy Daniels and Karen McDougal. Hence the hush-money payments and NDA's. Since this affected the outcome of the 2016 election, they were campaign expenses.
That's not the test for "campaign expenses." Also, it's not clear it impacted the "outcome" of the election. There is no evidence that anyone has presented that had voters known about Stormy and McDougall they would have voted another way. He already had a problem with some women voters, and those that were voting for him already knew him as a womanizer and adulterer. So, there is plenty of reasonable doubt as to whether it would have impacted the outcome of the election.
However, Trump and Cohen disguised the $130,000 payment to Ms. Daniels as 8 separate checks signed by Trump to Michael Cohen for "legal expenses".
Which itself is not illegal. An attorney and client are free to have a lawyer front some expense or payment and then say, "ok, in reimbursement, you'll just pay me extra legal fees to cover that." That's not a crime. That's no different than saying the lawyer can front a payment owed by a client to a creditor, and then the client will repay the lawyer by "sending the lawyer more business referrals..." or "delivering a priceless painting to the lawyer as compensation..." or "the lawyer will waive it as a courtesy to the client who paid millions in fees to the lawyer already..." or the lawyer might say "I tell you what, don't pay me back for those fronted expenses, and you just pay me a monthly retainer to keep me on as your lawyer."
If Trump had been honest about what this $130,000 was actually for, he wouldn't be facing felony charges in New York. But then again, Trump being honest about the true nature of the $130,000 payment would have defeated the overarching purpose of keeping his affair with this pornstar a secret for election purposes.
Well, right, becasue it also would defeat the purpose of keeping it secret from his wife and family, and under the "irrespective test" through the FEC, an expense that would be paid irrespective of its effect on the campaign is not a campaign expense. Therefore, even if there are two purposes for the payments, one election related and one family/spouse related, then it's not a campaign expense.
https://www.fec.gov/help-candidates-and-committees/making-disbursements/personal-use/
It's kinda like why Clothing is not a campaign expense. It certainly helps the campaign for a candidate to dress well, and be well-groomed and be cleaned and showered - and if a candidate was dressed in poor clothing, unwashed and with shaggy hair and unshaven and unkempt, it could and would impact the outcome of a close election. But, those are also personal expenses, and people need to buy clothes and pay for water for their showers, and buy soap and shave cream and razors and combs and go to barbers and such, but those are not "campaign expenses."
Clothing
The campaign cannot pay for attire for political functions (for example, a new tuxedo or dress), but it can pay for clothing of de minimis value that is used in the campaign, such as T-shirts or caps imprinted with a campaign slogan.
So, dressing in nice suits with new and cleaned and pressed ties and shirts makes a candidate look better and is clearly part of what markets a candidate to the public. But it's not a campaign expense, no matter how much it benefits the campaign - UNLESS - unless what? It's got campaign slogans and logos on it, becasue then it IS solely -- solely - a campaign expense, as the candidate would not have campaign slogans and logos on normal clothes. It's specifically and only for the campaign.
Another example is a vehicle -
Vehicle expenses
Campaign funds may be used to pay for a vehicle that is used for campaign-related purposes, assuming that the costs related to the personal use of the vehicle are de minimis, that is, such costs are insignificant in relation to the overall vehicle use.
So a dual use vehicle - for both campaign purposes AND personal purposes is not a campaign expense. But if you exclusively use a vehicle for the campaign, then it is a campaign expense (allowable for something "de minimus" -- which is an allowable incidental, minor or insignificant personal use).
So, a campaign bus is a campaign expense, but a candidate's Prius that he or she uses to get around town and go to the supermarket is not (even if he or she also uses it for the campaign).