Exit polls showed Al Gore winning in Florida. If they were correct, he was the next president of the United States.
Instead, results later showed George Bush winning by 537 votes. People said you couldn’t believe exit polls, and they lost
some credibility. The switch to Bush’s column gave him 271 electoral votes, just enough to win, even though he lost the
popular vote by more than 540,000! Statisticians began investigating and came up with a very plausible explanation. In
addition to Gore and Bush, there were several candidates, and one who attracted the most attention was Pat Buchanan a right-wing
conservative. In Palm Beach county, Buchanan was credited with 3407 votes, more than three times what he got in any other county.
This was especially notable because Palm Beach county is strongly democratic and a right-wing conservative would not be expected
to get anything near what he got. We investigate!
In Florida’s 67 counties, the regression which would predict Pat Buchanan’s vote total from Gore’s vote total is
Y
=80.74
+ .004144* Gore’s Total. This plot is shown next to the residual plot.
Gore
Buchanan
4000003000002000001000000
3500
3000
2500
2000
1500
1000
500
0
S 328.008
R-Sq 47.7%
R-Sq(adj) 46.9%
Fitted Line Plot
Buchanan = 80.74 + 0.004144 Gore
Gore
SRES1
4000003000002000001000000
8
6
4
2
0
-2
-4
Scatterplot of SRES1 vs Gore
The outlier in the residual plot at almost 8 standard deviations above the line, is from Palm Beach county, which is known
to be a very strong democratic county and thus votes for Buchanan should be correspondingly small. Yet Buchanan got
3407 votes! Did he really get this many votes? If we remove Palm Beach county, leaving 66 counties, the regression is
Gore
Buchanan
4000003000002000001000000
1200
1000
800
600
400
200
0
S 138.291
R-Sq 63.0%
R-Sq(adj) 62.5%
Fitted Line Plot with Palm Beach county removed
Buchanan = 110.7 + 0.002557 Gore
Based on this regression and Gore’s Palm Beach county votes, we would predict that Buchanan should get
110.7+.002557(268945)=798 votes in Palm Beach county. This is probably a high estimate because it is known that Palm
Beach county is strongly democratic, and a right-wing conservative would probably not get that many votes. Buchanan’s
vote total in Palm Beach county was 3407---almost 3.5 times his next best county.
Allowing him to get even a thousand votes, Gore would have won Florida by about 2000 votes. What happened? The
answer is provided by looking at the Palm Beach County ballot, known as the “butterfly” ballot. This was the only county
that used such a ballot, which you will see now.
Math 311 Fall 2008---The Florida vote in the 2000 Presidential Election
