This new found "public spiritedness" (at the point of a Congressional skewer) will merely result in greatly increased trading of oil futures outside the US!
Money flows at the speed of light to where the biggest bang for the buck can be found and there is no more fungible commodity on the planet than oil!
I wonder where the huge pension funds and international government investment entities will trade?
If ERISA is held over the pension funds' heads (as it should be), they won't move offshore -- they'll get out of the futures game entirely, which is also as it should be.
Neither will the investment banks move offshore; when they trade for their own account, they're already classed as specs, and as such subject to position limits.
The specs will indeed go, like lightning, to other exchanges IF they see an advantage in doing so. If the current situation is properly handled, there will be no such incentive.