The following entry replicates information posted at my election site,
election.princeton.edu. The main point is that pre-election polls match what happened in Ohio and Pennsylvania, but not Florida.
I chose these three states because so many polls were available for them.
The graph below shows all state polls in Florida, Ohio and Pennsylvania in the two weeks preceding the election. The gray band indicates ±1 standard error of the mean for the last seven days, and is about half the width of the 95% confidence band that you might be used to seeing.
The arrowheads indicate the final announced outcomes. Ohio and Pennsylvania polls were consistent with the final outcome, but Florida polls were not consistent.
Pennsylvania polls indicated a Kerry win by 2.1 ± 0.7%; the final result was Kerry by 2.2%.
Ohio polls indicated a Bush win by 1.0 ± 0.7%; the final result was Bush by 2.5%. This could be accounted for by the trend toward Bush in the last five days.
Florida polls indicated a Bush win by 1.4 ± 0.9%; the final result was Bush by 5.0%. This final result is off by 4 SEM. It is also in the same direction as the claims of voting fraud made based on county-level data.
Although not definitive, these data are at least consistent with the suggestion that something unusual happened in Florida, either in the 33 polls conducted in the final weeks of the campaign, or in actual voting.