conservation. Natural gas In his 2008 book, The First Billion is the Hardest, Pickens noted a belief in the "peak oil" theory. He later altered that position, noting technical achievements of the domestic oil and natural gas industries in utilizing horizontal drilling and fracking to unlock shale oil and gas reserves. He called for the construction of more nuclear power plants, the use of natural gas to power the country's transportation systems, and the promotion of alternative energy. Pickens's involvement with the natural gas fueling campaign was long-running. He formed Pickens Fuel Corporation in 1997 and began promoting natural gas as the best vehicular fuel alternative. Reincorporated as Clean Energy Fuels Corporation in 2001, the company now owns and operates natural gas fueling stations from British Columbia to the Mexico–U.S. border. Political activity Since 1980, Pickens made over $5 million in political donations. He was a financial supporter of President George W. Bush and contributed heavily to both his Texas and national political campaigns. In 2004, Pickens contributed to Republican 527 groups, including a $2 million contribution to the Swift Vets and POWs for Truth which ran a campaign asserting that Bush's rival, John Kerry, exaggerated claims about his service in Vietnam, and $2.5 million to the Progress for America advocacy group. In 2005, Pickens was among 53 entities that contributed the maximum of $250,000 to Bush's second inauguration. On July 16, 2007, Pickens wrote an article for National Review supporting Rudy Giuliani for president. "In Rudy Giuliani, a gracious and committed public servant I've known for many years, we see that rare blend of big-picture vision and proven track record of achieving the 'impossible.' We see a forward-looking, accomplished executive eager to tackle the challenges of today's America and ensure that tomorrow we wake up stronger, freer, and more united than ever before." Pickens was an executive committee member of the Rudy Giuliani presidential committee. Pickens focused his advocacy on alternative energy such as solar and wind. The Washington Post says that "perhaps the strangest role" Pickens "has fashioned for himself is his current one: the billionaire speculator as energy-wise man, an oil-and-gas magnate as the champion of wind power, and a lifetime Republican who has become a fellow traveler among environmentally-minded Democrats – even though he helped finance the 'Swift boat' ads that savaged" John Kerry's presidential campaign. In an editorial, The New York Times reported Pickens "has