All his being a billionaire because he is so smart and such a great businessman will be proven to be fake. The thing he always accuses others of. Most of the Magats won’t change their minds but he already knows he is a spectacular failure who lies and cheats as the only way his business ever turned a profit. And it might ultimately ruin the only successful enterprise he’s ever had; conning the poor magats into sending him money.

So grifting for campaign contributions sounded like a good idea - and it's worked so well for him that he never gave it up. Even while he was in office, he farmed out his responsibilities and continued to hold "rallies..."