Obvious
The clear answer lies with campaign financing laws, which are in themselves backwards and broken. Additionally, when you look at how much each party receives from Big Oil, you can see a very vivid picture being developed. Although both parties receive campaign contributions from Big Oil, it is clear that Republicans receive a much greater sum [source].
Lobbying
This is where we enter into a very gray area. Every company has the right to lobby for their own interest. The problem being of course, they are able to lobby at a level that far exceeds the level that we mere mortals are able to. Case in point: Obama calls for the repeal of Big Oil tax breaks, and shortly after the Koch Brothers were vowing to contribute more money to labeling the President as the "fall guy" for the high oil prices. They are trying to blame his energy policies as the reason for the high prices.
Reality
In reality, it is the President's energy policies that have them very worried. Oil has found a market in many sectors (plastics, agriculture, gas, etc). When you have a handful of companies that control all of the world's oil supply, and there is a high demand for that supply, then you are set to make a considerable fortune. This is what Big Oil has done for years.
In comes the President with his energy policy, aimed to reduce our reliance on oil and open up our markets to other forms of energy. By taking an "all of the above" approach [source], the President is taking on this task on all fronts (improved fuel efficiency for vehicles, develop new technologies, etc). The fact is, the President is right. Not just for ensuring that America is not put into a choke-hold, not just to stabilize the market, not just for the environment, but to build new market (i.e. create jobs).
Conclusion
So when you read about how much money Romney's campaign has received, understand that his money came from a desperate industry. An industry who is going to lose their "captive" audience. An industry that will have to compete in the market place with other energy sectors (hydrogen, solar, etc). We will see how much gas costs when it is no longer the only option for fueling our vehicles.
If the Koch brothers would invest the money they have committed in defeating Obama, they just might find themselves industry leaders in these emerging markets. Instead they choose not to innovate and relying on things staying the same. Good luck with that!
[Disclaimer: Koch Industries is not Big Oil per say, they are just intimately entwined]
