Over at The New Republic the other day, Jonathan Chait penned a piece about just how much Sen. John McCain (R-AZ) has changed his positions over the years.  Not just once, but twice, he has significantly re-invented himself.  Here is my favorite paragraph so far:

Republicans who fought the legislative battles of those days now regard the prospect that McCain could become their party’s standard-bearer with incredulity. These figures are stumbling around in rage and disbelief, like Jimmy Stewart in It’s A Wonderful Life discovering that his beloved hometown has been taken over by Henry Potter. Former Senate Republican Conference chairman Rick Santorum bitterly noted that “almost at every turn, on domestic policy, John McCain was not only against us, but leading the charge on the other side.” Former House speaker Dennis Hastert–in what, by his somnolent Midwestern standards, counts as an angry tirade–complained that McCain usually “allied with Democrats.”
Maverick Vs. Iceman

Thanks to Tom Regan over at NPR for turning me onto this article.