I think the problem all these arguments have is that the problem isn't clearly defined, and the different definitions call for different solutions.
Problem 1) Environmental, i.e. greenhouse gasses (not one I particularly believe in, but it is one definition). To reduce greenhouse gas emissions we would need to decrease our use of oil. The solution then would be high oil prices. With taxes on oil sufficiently high and with an energy policy that focuses on alternative sources of fuel (like nuclear, solar, etc.) raised CAFE standards would be redundant and unnecessary.
Problem 2) Political, i.e. depending on foreign sources of energy. The solution to this problem would include not only higher prices and investment in alternative energy sources, but also increased domestic production including other greenhouse gas emitting sources like coal(in contradiction to the environmental solution).
Problem 3) Economic, i.e. cheap energy is good for the economy. For this we want lower gas prices for the sake of the economy. This contradicts the solution for both the environmental and political problems. We also want to increase domestic production, which contradicts the environmental solution. Like both other problems we want ready access to alternative energy sources, but in this case not at the expense of oil but in addition to it. This is also the only case where higher CAFE standards might make sense, because we might want to decrease the use of gasoline by cars to keep the price of oil low. The effect would likely be small though given that oil is a global market.
Personally I think the economic problem is the most important to address.
Good analysis. Note that in my advocacy of increased nuclear power, the byproduct is the production of biofuels from agricultural feedstock. This would allow continued use of fuel for transportation with no net greenhouse emissions. (We just have to make sure Yucca Mountain is a safe nuke waste repository.)