Corporate profits are easily reduced to zero by say... Paying fat bonuses to ceos. All high corporate taxes do is encourage companies to dispose of the profits before the end of the tax period.
Those bonuses are then taxed too, which should give you a hint why corporate tax is a bit daft to begin with.
Corporate tax is, by and large, a fiction to placate voters. It could (should?) be replaced with a more flexible system that isn't as susceptible to the usual deduction and profit shifting.
