Basically, Michael Cohen took out a second mortgage to quickly pay off Stormy Daniels to keep her quiet and paid her through some shell corp, rushed after the Access Hollywood tape came to light...I would think the contract should spell out the consequences, but we don't have it available, so we'll see.
His Presidential candidacy could not withstand being hurt if the Stormy affair came out too, on the heels of him already defending the Access Hollywood tape as just Locker Room Talk. So Trump decided to pay her off in exchange for a Non Disclosure Agreement.
Well, the main issue that I am aware of besides some of the technical Campaign financing issues is that when the trump org paid Cohen back and paid him his fee for doing all this hush money work, including him taking a second mortgage, and paying the other $100 grand to silence Karen McDougal through a catch and kill at the National Enquirer as well...
the Trump Org illegally reimbursed him $500,000 as some business expense for a new audio system and equipment....avoiding Michael's income earnings being taxed, and allowing trump org to illegally write it all off as a business equipment expense on their taxes.
Cohen spent some of his time in prison for this crime already....