Mark Schmitt starts this article by arguing that John McCain is "a worthy heir to Barry Goldwater's Senate seat." That isn't what's interesting about the piece, though—the good part comes when he moves beyond debating McCain's political views and starts asking how much those views matter:
I'm really tired of all these discussions about whether McCain, or any politician, is "really" a moderate or a conservative or anything else. I don't like the whole mode of analysis that assumes a politician has some "real" core of beliefs and then various positions he or she takes are either "real" or "political." That whole analysis is based on the cult of authenticity of which McCain, and to a lesser extent Bush, have been the greatest beneficiaries.
Politicians are aggregations of their instincts, values, and political circumstances and conditions, the pressures put on them and the niches that are available. (For example, there's no niche in the Republican presidential primary field for an independent moderate or a pro-choice candidate, and so McCain is simply not going to be either of those things, whatever his inner core is.) And that's not totally inappropriate in a democracy, where people are elected to represent and serve the public. Consider that even on a deeply moral issue, capital punishment, many moderate Democratic politicians who probably were instinctively uncomfortable with the death penalty nonetheless found a way to live with it in the 80s and 90s. Obviously, people grow up with instincts and values and experiences that shape their general view of the world, but within those worldviews, there's a lot of room for various policy positions in response to external pressures and circumstances and opportunities.
Schmitt also notes that "'authenticity' is an important political tool in its own right. And voters are malleable as well, supporting a political candidate they view as genuine, even if the candidate's views differ greatly from their own, as I discovered in New Hampshire in 2000 where some number of independent, socially liberal voters chose to vote for the hot McCain in the Republican primary over Bill Bradley in the Democratic."