Well, and more than that, if you think of the center as being where the federal government is now (rather than as some hypothetical midpoint between hypothetical endpoints), the country in aggregate can very easily be Right of Center or Left of Center--in the early 80s, for instance, much of the country had rejected the Great Society programs that were still very much central to the federal government's policies.

Of course, the problem with that is that a statement like Sen. McCain's is simply false. Popular policies are far to the left of our current actual policies. But it is a statement with a truth value, just not a good one.

Thanks,
-V.