Politics was never intended to be a real business until the Obama administration began using taxpayer money to buy automobile companies, investing in varying solar companies and otherwise "stimulating the economy".
Well, it's always been a business, certainly from the founding onward. Assumption of the Revolutionary war debt, speculation involving Federal lands, the Erie Canal financing, etc., etc.
And actually it seems that a great many of those who invested in him now have buyers remorse.
GM is happy, and those on the inside of the solar business didn't lose their own money. It's a matter of who gains and who loses, and not everybody is always happy, but the insiders rarely take a hit.
His resume is rather murky but if you say he was a successful businessman before entering public office he might well have been. You have no reason to lie.
His resume is pretty straight forward, hiring employees, rounding up investors and financing, organizing and administration of his business, planning, it's all there.