How to address the situation is where the three disagree.
Republican Saxby Chambliss, Democrat Jim Martin and Libertarian Allen Buckley approach the issue from perspectives that reflect their general philosophies. When voters decide whether to return Mr. Chambliss to Washington or one of the two challengers, the pain of filling up gas tanks is likely to be on their minds.
Mr. Chambliss wants voters to know he recognizes their concerns.
During the summer, he was one of the leaders of a bipartisan group of senators nicknamed the Gang of 20 that pushed a proposal to change tax breaks for the five largest oil companies, create tax incentives for alternative-fuel car buyers and open up more areas to offshore drilling. Conservatives blasted the plan as a tax increase on those oil companies, and Mr. Buckley said Mr. Chambliss gave in on his own position for the sake of bipartisanship.
The senator's press secretary, Michelle Grasso, disputes the charges.
"It wasn't a tax increase. It is only a removal of an incentive," she said. "It would just shift their incentive."
Mr. Martin described the plan as flawed for neither addressing short-term price relief at the pump nor long-term energy independence.
Mr. Chambliss was again involved in energy policy after Hurricanes Gustav and Ike created gas shortages in Georgia because refineries lost electrical power. He and Gov. Sonny Perdue won a waiver from the U.S. Environmental Protection Agency to use more plentiful gasoline blends that also generate greater emissions. But Democrats blamed Mr. Chambliss for not acting sooner - even before the storms hit - to get a waiver.
Ms. Grasso called such criticism unfair.
"No one foresaw the shortage," she said.
Now Mr. Chambliss has signed in support of a plan by T. Boone Pickens for extending federal tax credits for electricity-generating windmills and tax money for upgrades in the nation's power grid.
"We cannot continue to be dependent on foreign countries for our oil," said Mr. Chambliss. "Much like the ideas I have advocated in Congress, Boone Pickens provides a comprehensive approach to addressing our energy problems here and now on our own soil in a responsible way."
On the other hand, Mr. Buckley's approach for reducing U.S. dependence on foreign oil relies on rewards rather than tax breaks or subsidies, which he describes as handouts. He would grant financial rewards to companies that successfully produce low-emission fuels.
"If they can come out with something that's cheaper and cleaner burning, they ought to be able to sell that," he said.
At the same time, Mr. Buckley would adjust the federal motor-fuel tax to reflect emissions while keeping the revenue what it is today. So, in five years if half the cars run on hydrogen with zero pollution the tax would also be zero, and vehicles with batteries that must be disposed of and use electricity from low-polluting plants would be taxed at maybe half the rate of today's fuel. Those reductions would require the doubling of the federal tax on gasoline to keep them revenue neutral.
Mr. Buckley has no objection to offshore drilling as a short-term solution as long as it can be done in an environmentally safe way.
The other challenger, Mr. Martin, favors exploring all energy sources to reduce dependence on imported oil, but he frequently talks about wanting to shift to environmentally friendly fuels.
"We need to move quickly away from our dependence on foreign oil and move toward alternative fuel," he said. "That will create an enormous economic renaissance in this country as we, using our technology, move away from oil and gas and move into alternative fuels."
Mr. Martin would not block offshore drilling, nor would he support subsidies for one type of fuel production over another, noting that corn-ethanol subsidies which drove up the price of foods proved the government shouldn't favor particular technologies. Yet, he does call for "reinvesting our resources into the development of alternative sources of energy" as part of a comprehensive strategy.
Unlike Mr. Chambliss or Mr. Buckley, he doesn't offer specific proposals on how he would shift domestic energy consumption other than saying it will take a comprehensive plan that's coordinated with federal tax policy. However, he would insist on greater regulation of the commodities markets, arguing that oil speculators drove up the price of gas during the summer.
Overall, he argues that energy policy should stress the long-term strength of the economy and of the environment.
"The important issue here is sustainability," Mr. Martin said.