It was booked as a legal expense. It wasn't.Trump is allowed to spend however much he wants of his own money on his own campaign. There is no limit. The payment to Stormy was Trump's own money. Nothing remotely illegal. Edwards was using campaign donations.
"On May 24, 2011, ABC News and the New York Times reported that the U.S Department of Justice's Public Integrity Section had conducted a two-year investigation into whether Edwards had used more than $1 million in political donations to hide his affair and planned to pursue criminal charges for alleged violations of campaign finance laws."
You're badly misinformed.