Two further points. One — in a lot of ways “McGovern!” is the “Munich!” of campaign journalism, probably an analogy we should all just agree to do without. The circumstances of the 1972 campaign were very much circumstances of 1972 (see Rick Perlstein’s Nixonland if you don’t believe me) and it’s exceedingly unlikely that anything like that will happen again.
Two — it’s important to remember that by far the biggest source of uncertainty about the November presidential election has to do not with the Democratic primary campaign, but with objective reality. I don’t believe that the situation in Iraq or the economy will look radically better in November than they do today, but in principle either or both might. Something like that would make John McCain — a popular and skilled politician who gets good press — extremely hard to beat. But if the economy continues to be weak and Americans keep dying in a war that offers no light at the end of the tunnel, it’s very hard for McCain to win. This kind of thing — the inherent unknowability of things like the Q3 GDP growth rate and the future course of inflation, the possibility of new foreign crises or dramatic changes in Iraq — is what makes the outcome uncertain. The differences, qua candidates, between Clinton and Obama are small in comparison to this haze of uncertainty.