Just a guess. From the blog of Time Magazine's White House correspondent:
Previewing the final quarter of Bush's presidency, officials disclosed to Time that the Administration is formulating a huge energy initiative designed to "change the whole nature of the discussion" and challenge the g.o.p., Democrats, the oil and electricity industries, and environmentalists. An adviser said Bush's views about global warming have evolved. "Only Nixon could go to China, and only Bush and Cheney--two oilmen--can bring all these parties kicking and screaming to the table," the adviser said."