Trump also attacked his opponents for accepting donations from the pharmaceutical industry.  Since Trump is rich, he can finance his own campaign.
Sanders also has an issue with big money in politics and won't take corporate donations. He is on track to out fund raise Clinton for the third month in  row.  The average donation is $27. And yet people fear he will take over the local grocery store. If you want to know how people will run the presidency, look at how they campaign.