It's hard to imagine that another John McCain profile could be interesting -- by this point the man's character and ideology seem completely transparent -- but New York's Joe Hagan pulls it off. (New York magazine has published some hugely impressive political coverage under Adam Moss.) It's hard to summarize the piece, but it gets at McCain's mentality -- angry, entitled -- and the rifts among his advisers.

Meanwhile, Matthew Yglesias invokes the liberal conventional wisdom on McCain:

After losing the 2000 primary he spent several years acting like a huge sore loser and racking up one of the least-conservative voting records of any Republican. Then he tacked right starting in 2004, and after losing to Barack Obama’s he’s been acting like a sore loser again.
I liked it better when sore loserdom pointed in the direction of opposition to Bush’s tax cuts than in the direction of opposition to carbon pricing, but it’s really two sides of the same coin.

The trouble with this analysis is that McCain's ideological heterodoxy began years before, with his advocacy of campaign finance reform. And his most heterodox position, opposition to tax cuts, began in 1999. Well before George W. Bush won the 2000 GOP nomination, McCain was attacking Bush's tax cuts plan as not only fiscally irresponsible but an immoral sop to the rich. This was an astonishing position. You can find Republicans straying from the party line on climate change, immigration, campaign finance reform, or other issues where McCain staked out liberal ground. Every once in a while you can find an elected Republican who expresses some muffled reservation about tax cuts -- but only on grounds of fiscal responsibility. To describe tax cuts for the rich as tax cuts for the rich, and to attack them on moral grounds, was and is totally verboten in the GOP.

Now, it's possible and even likely that pique with Bush drove McCain further to the left after Bush won the nomination. But to interpret his entire leftward shift as sore loserdom is just not a tenable analysis. I think that McCain's constant retail politicking in 1999, especially the endless town hall question and answer sessions, broke him out of the Republican bubble and put him in touch with the reality of an economy that did not need tax cuts, especially for the rich. He became unmoored from Republican domestic orthodoxy, and that process fed on itself as he became alienated from the party establishment. But starting in 2004, McCain decided to seek the 2008 GOP nomination and has been fervently abandoning every element of his heterodoxy, to the point of outright comedy, such as denying that he ever considered himself a maverick.