... since he started running for president last year, McCain has largely downplayed climate change. He hasn't declared support for a tougher and more detailed bill, proposed by Senators John Warner and McCain ally Joe Lieberman. And his top domestic policy adviser recently suggested that McCain might not even stand by his own weaker bill, telling a reporter: "He wasn't so much committed to the bill as to an issue."

Most important, McCain has not made global warming a rhetorical priority. Since he began his White House run, he hasn't given a single speech that we're aware of devoted to the issue, or released an ad that mentions it in any detail. In general, McCain has based his pitch to voters, both before and after clinching the GOP nomination, on his personal biography, his national-security experience (particularly his support for the troop surge in Iraq), and his straight-talking persona. No fair assessment could conclude that global warming, or any other environmental issue, has been "central" to McCain's campaign.