Peter, I generally agree with your take as a response to the generic question: “What was the single biggest factor leading to McCain’s poll collapse?” However, I think as a means of assessing this election and where Republicans go from here it is a mistake to omit the follow up: “But could it have been closer?” (Both of these assume, of course, that John McCain will not be able to pull off a shocking upset.)
It is perfectly fair, and quite helpful for Republicans, to examine whether a more ideologically grounded candidate would have fared better — and will in the future. It is quite appropriate once we know the final figures to see what percentage of the conservative base turned out, and to assess Sarah Palin’s role in that. It will be useful to consider whether a charismatic and articulate messenger has simply become a necessity in presidential politics. In essence, I’m suggesting that a fatalistic assessment of 2008 (“We were doomed no matter what”) is untestable and ultimately not very productive.
As to the tone of that assessment, I concur that calmer and more reasoned is better than hysterical and more emotive. But there are lessons to be learned from the style and substance of the Republican campaign and candidate whom Republicans selected.