There is a strange meme in the blogsphere—most recently made in comments here by Movie Guy—that Obama “should have a double-digit lead over McCain at this stage as has been the case with previous presidential primaries.” So I went searching for double-digit leads among two-person Presidential races in the past several elections.
August 2004 (Bush [I] v Kerry):
Not a double-digit lead among them. How about 2000?
Bush v Gore, per Gallup:
A severe outlier early, and another slight outlier (almost ten points, but not quite) later on, but still no sustained double-digit leads. Maybe 1996?
Clinton [I] v Dole, Gallup Poll Trends:
A-HA! There is it; the source of the belief that one should have “double-digit” leads. A popular, incumbent president (“longest peace-time economic expansion in history”) running for re-election against a man who doesn’t even seem to be trying hard. (Ask “Hideo Nomo of the Brooklyn Dodgers.”)
But, oops. It’s also not the whole story. The whole story for 1996 runs more like Clinton (I) v Dole and Perot:
Again, Clinton is a popular, incumbent President (all things Obama is not) running against a man who is increasingly making it clear he doesn’t want the job (and a man whose candidacy was widely seen as equivalent to a “protest vote” against, e.g., NAFTA). So it seems reasonable to assume that many of the “undecideds” were not going to break his way and were deciding which protest vote was more reasonable.
But MG may suggest that I am politically naive to suggest that all of the Undecideds would break away from Clinton, and he’s probably correct. But it similarly seems reasonable to assume that a notable majority would break that way—say, 75% of the undecideds.
So even a popular incumbent cannot sustain a double-digit lead (though the negatives would still, of course, leave him winning with a large plurality of the vote—which is what happened). And the only times we see a convincing double-digit lead is when a substantial third-party candidate is excluded from the polling, and one of the candidates is a popular Incumbent.
Don’t get me wrong; I agree with Paul Krugman (contra lerxst) that Obama’s campaign isn’t so appealing as it could and should be. But in a two-party race* with neither candidate being the Incumbent,** expectations of a sustained double-digit lead, even over a short period of time, are absurd.
*Pending evidence of a large groundswell for Bob Barr and One of Obama’s Classmates on the Libertarian line or a rally amongst pro-Prohibition forces in the face of the Amethyst Initiative.
**In name, at least.