This certainly explains a few things

McCain sees himself in Teddy Roosevelt mold - International Herald Tribune

"I count myself as a conservative Republican, yet I view it to a large degree in the Theodore Roosevelt mold," the presumptive Republican presidential nominee said, referring to Roosevelt's reputation for reform, environmentalism and tough foreign policy.

So what's the problem with this? Teddy Roosevelt was a lot of things, but a conservative he was not. He was a populist, plain and simple. That's pretty much what McCain seems to go for as well.