Seems a bit different, since with Trump he was a candidate paying other people with his own money, while Edwards was a candidate receiving money from other people.
Did the donors pay the gift tax? The annual federal gift tax exclusion is $15,000 for the 2018 tax year. This is the amount of money that you can give as a gift to one person, in any given year, without having to pay any gift tax.
Even if the cases were EXACTLY the same, Edwards was a Democrat. There is a different set of rules for Democrats. They can do and say anything, pay off their mistresses with taxpayer funds, sell state secrets, drive drunk and drown innocent young women, sell out our country for money with a fake charity, have sex with 19 year old interns in the oval office, be a former leader of the KKK, be otherwise outright racist, etc. etc. etc.
Republicans can be innocent and their lives and livlihoods ruined by innuendo and false allegations. The difference here is party affiliation. Republicans cannot expect equal justice. In fact there is no justice for Republicans. They have pretty much made it illegal to be a Republican.