[elfman2]

"The nom-paranoid explanation of the party distribution is that some right-leaning Independents declared themselves as Republicans after deciding to vote for Bush."

That’s not only non-paranoid, it’s unnatural . 10-20 percent may change candidates overnight, but not party affiliations.

[labard1]

"20 percent may change candidates overnight, but not party affiliations."

Absolutely right! Even in states where party affiliation is not registered with the state, self-identification of party affiliation over time is normally VERY slow to change. It often takes 10-20 years between the time people start voting for candidates of the other party until they change their own party self-identification.

Look at the South's move to the GOP for the most recent massive scale switch example. That's what political behaviorists were saying in the 1930s, and nothing since then has undermined it.