Support for development of fuel sources such as wind and solar power has diminished in the United States during the past year, a survey found. The March 7-11 poll, conducted by the Pew Research Center for People & the Press, found 52 percent of those responding indicated support for alternative fuel was more important than increasing oil, coal and natural gas production, while 39 percent indicated expanding exploration of coal, oil and gas was the more important of the two choices. Although a majority went for alternative fuels, support for solar, wind and hydrogen power was not as popular as it had been in March 2011, when 63 percent indicated that was their favorite choice, while 29 percent chose coal, oil and gas exploration. Respondents who identified themselves as Republicans were more apt to have changed their preferences -- with 33 percent indicated support for alternative energy sources, down from 47 percent in 2011. The survey found \"as in the past ... there continues to be broad public support for an array of policies aimed at addressing the nation\'s energy supply.\" Nearly 80 percent overall indicated support for improving fuel efficiency in cars, while nearly 70 percent indicated support for federal research for alternative energy sources. Sixty-five percent indicated support for improved rail, bus and subway systems. Concerning the controversial method of mining called fracking, 37 percent indicated they have only heard a little about it and 37 percent, indicated they have never heard of it. Only 25 percent indicated they had heard a lot about it. A majority -- 52 percent -- indicated support for fracking, a figure held up mostly by Republicans, 73 percent of whom indicated they supported fracking, compared to 33 percent of Democrats. The poll was based on 1,503 interviews and has a margin of error of 3 percentage points.