Let's talk about tax subsidies for big oil companies.
A subsidy is a payment to somebody. The government does not pay the oil companies a single dime. Perhaps you're thinking of ethanol.
You're thinking (heh) of a tax deduction and the deduction the oil companies get is the same deduction every other corporation, big or small, may use.
And as has been noted up-thread, corporations never pay taxes, they always pass the cost to consumers.
Hence why he chooses to debate at the DUmp.
Would that he'd register here.
Surely he's not scared of a timid woodland creature.