Trends for 2008

[zorkpolitics]

Trends, of course, develop over time, so predicting the outcome in 2008 will depend not only on what data set one uses, but how it is interpreted.

In the current polarized and partisan political situation, only swing states matter.  Either they are in play and the election will be close (like 2000 and 2004), or one side has such a dominant position they don't matter (like 1996 or 1988).

2000 and 2008 provide an excellent data set since one candidate, Bush, acts as an internal control to identify trends.  Looking at the increase in Republican (Bush) vote in the two elections, and continuing that trend, predicts a near Republican sweep of the swing states.

Below is a list of swing states and their change in % vote for Bush from 2000 to 2004, with a prediction for 2008 based on the same percentage change.  This predicts an easy Republican win in 2008:

                Bush%     Bush%   Projected  Winner
                 2000   2004      2008
MN             45.5   47.6   49.7   R
MI             46.1   47.8   49.5   D
PA             46.3   48.4   50.4   R
OR             46.5   47.2   47.8   D
WI             47.6   49.3   51.0   R
NM             47.9   49.8   51.7   R
NH             48.1   48.9   49.7   R
IA              48.2   49.9   51.6   R
FL              48.9   52.0    55.1      R
NV             49.5   50.5   51.5   R
OH             50.0   50.8   51.6   R
CO             50.8   51.7   52.6   R


Alternatively, we can assume most of Bush's gains in 2004 were due to the incumbent effect.  The 5 incumbents re-elected since 1950 all increased their margin, from 2% (Eisenhower) to 17% (Nixon).  If so then the real trend is how the swing states changed relative to the national result.  One can predict the 2008 result by subtracting the 2.8% national gain Bush had from his 2004 result in the swing states.  This predicts an sweep of the swing states by the Democrat:

                        Projected
                 2000   2004    2008
MN             45.5   47.6   44.8   D
MI             46.1   47.8   45.0   D
PA             46.3   48.4   45.6   D
OR             46.5   47.2   44.4   D
WI             47.6   49.3   46.5   D
NM             47.9   49.8   47.0   D
NH             48.1   48.9   46.1   D
IA              48.2   49.9   47.1   D
FL              48.9    52.0    49.2   D
NV             49.5   50.5   47.7   D
OH             50.0   50.8   48.0   D
CO             50.8   51.7   48.9   D

Same data, 2 interpretations, which will come closest to the 2008 result?