(CNN) -- In late June, the U.S. Senate passed an energy bill that would raise gas mileage standards for the first time in 20 years and fund research on alternative energy sources.
High gas prices and low mileage are among the factors behind an apparent shift in the nation's energy debate.
The bill's proponents call it a breakthrough in the nation's energy debate, saying the focus is shifting from reliance on fossil fuels and foreign oil toward renewable fuels and green technology.
The measure comes amid another summer of high gas prices, state and local conservation efforts and a presidential campaign where voters and candidates say the issue is key.
So is a critical mass building among Americans and legislators for changes in U.S. energy policy? Or are these efforts simply blips on the radar as Americans continue to drive SUVs and Hummers?
A recent analysis by the Gallup Poll showed energy as Americans' fourth most-important priority for Washington, below Iraq, terrorism and national security, and the economy.
The analysis also showed Americans prefer energy conservation over more production, and that a large majority also favors tightening emissions standards and developing alternative sources of energy.
When asked to rate the importance of issues in voting for a presidential candidate next year, 43 percent of Americans said gas prices would be "extremely important," according to a May poll by Opinion Research Corporation. The percentage was tied with health care and below Iraq, terrorism and education.
Democratic and Republican presidential contenders seem to have taken note of voters' discontent.
"It's a national security issue. It's a health care issue," Connecticut Sen. Chris Dodd, a Democrat, said during a CNN presidential debate in New Hampshire in June. He touted a plan that would require a standard of 50 miles per gallon for automobiles by 2017.
New Mexico Gov. Bill Richardson, a Democrat, touted an "Apollo program" -- referring to the 1960s effort that put men on the moon -- that would reduce dependence on foreign oil by more than half and reduce greenhouse gas emissions by 80 percent.
During the Republican presidential debate in New Hampshire two days later, many candidates said much the same thing.
Former New York City Mayor Rudy Giuliani, a Republican, also called for an "Apollo program" and said reducing foreign dependence on oil was intrinsically tied to national security.
"It's frustrating and really dangerous for us to see money going to our enemies because we have to buy oil from certain countries," he said. "We should be supporting all the alternatives."
Former Massachusetts Gov. Mitt Romney, a Republican, said oil companies ought to play a part in rebuilding old infrastructure, which would increase efficiency and possibly reduce costs.
"Big oil is making a lot of money right now, and I'd like to see them using that money to invest in refineries," Romney said. "Don't forget that when companies earn profit, that money's supposed to be reinvested in growth and our refineries are old."
President Bush, in his State of the Union address this year, announced an initiative to cut U.S. gasoline consumption by 20 percent over the next 10 years through a combination of alternative fuels and more efficient automobiles.
Several months later, during a speech at an Alabama nuclear energy plant, he also spoke of the promises of nuclear energy, coal, ethanol and cars that could run on rechargeable batteries.
Meanwhile, on the state and local level, several developments signal a possible shift among mayors, governors and state legislatures toward energy policies that focus more on renewable fuels and conservation measures.
Minnesota Gov. Tim Pawlenty, a Republican, announced the "25 by 25" program last year, with a goal that 25 percent of the energy produced and used in the state come from renewable sources by 2025.
The Nevada legislature has voted to increase the percentage of renewable resources in how the state produces electricity in four out of the last five sessions, according to the National Governors Association.
Massachusetts Gov. Deval Patrick, a Democrat, announced a plan in late June to reduce high energy costs in the state within the next three years through conservation measures.
And New York City Mayor Michael Bloomberg unveiled PlaNYC this summer, which includes 127 proposals to reduce greenhouse emissions by 30 percent by 2030 and a congestion charge for driving through certain parts of Manhattan.
When asked by CNN.com if efforts such as these were evidence of momentum toward a shift in energy policy, many readers said they were skeptical about the rhetoric of lawmakers and their political will.
"I can guarantee that whatever is 'done' will take place only to serve the benefits of those corporations directly affected by these issues," wrote Ryan Bate of Portland, Oregon.
"Change in U.S. policy? You must be joking," wrote Dean Cassano of Lakeland, Florida. "Washington is sold out to the environmentalists and tourists. The 1973 oil crisis did nothing to wake us up. We should have been drilling in [Alaska] and the Gulf ever since."
Ilene Lopez of Vero Beach, Florida, questioned whether American society actually wanted change. "The critical mass for change is still not a reality since so many people are still buying into the bigger is better motto of America," she wrote.
Cristian Crespo of Valley Village, California, said he found it ridiculous that automakers hadn't yet come up with a way to combine fuel efficiency with luxury provided by a SUV.
"It's not that Americans don't want to be environmentally friendly, it's just that we don't have much of a choice," he wrote. "As an SUV driver, telling me that my only alternative is a Toyota Prius or a Honda Civic is like telling me to eat beef jerky when I'm used to filet mignon." E-mail to a friend