Presidential Forecast, 7/22: The Decisive States

by: Chris Bowers

Tue Jul 22, 2008 at 15:15

Since the last update, there have been new polls from Alaska, Georgia, Maine, Michigan, New Hampshire (2), North Carolina and Ohio (2). The only category changes are downgrades in Michigan, from "Solid Obama" to "Lean Obama," and in Ohio, from "Lean Obama" to "Toss-up."

My two main goals with the presidential forecast are accuracy and clarity. With that in mind, I will be adjusting the forecast somewhat over the next couple of days. In particular, I will now focus on a more narrow set of "decisive states," that will determine the election. Here is a preview:

Swing State Overview

State	EV's	Obama %	McCain %	Margin	Obama Total
Obama Base	210				210
Pennsylvania	21	47.3%	40.3%	+7.0%	231
Michigan	17	45.5%	38.8%	+6.7%	248
New Mexico	5	46.8%	40.5%	+6.3%	253
Iowa	7	46.0%	39.8%	+6.2%	260
New Hampshire	4	45.8%	41.0%	+4.8%	264
Colorado	9	46.5%	43.0%	+3.5%	273
Virginia	13	46.8%	44.8%	+2.0%	286
Ohio	20	45.3%	44.0%	+1.3%	306
Nevada	5	42.3%	43.0%	-0.7%	311
North Dakota	3	43.3%	44.3%	-1.0%	314
North Carolina	15	43.6%	44.8%	-1.2%	329
Missouri	11	43.8%	45.4%	-1.6%	340
Indiana	11	43.3%	45.3%	-2.0%	351
Montana	3	43.3%	46.0%	-2.7%	354
Florida	27	43.2%	46.0%	-2.8%	381

The basic idea is that, at any given moment, I want to be able to highlight both the broad swing states, and the truly decisive, uber-swing states.  Right now, polling strongly suggests that Colorado, Ohio and Virginia are the three most important swing states. Fortunately for Obama, he would only need to win one of those three states, and he currently leads in all three. McCain would need to sweep those three states, but currently trails in all three. In fact, McCain could even sweep all three, but lose Nevada, and then still have Congress hand Obama victory in the event of a 269-269 tie. Thus, Nevada becomes the fourth most decisive state.

Since I probably can't match either Pollster.com or fivethirtyeight.com for total information availability, I am trying to provide the quickest, easiest to understand guide to the current standings in the Presidential election. What I can't match in terms of total raw data, I will try to make up for with clarity and transparency (without, of course, losing any of the accuracy). I hope this chart is a step in the right direction, but please let me know what you think.

Complete state by state details in the extended entry.

Updated: New polls from Colorado and Florida has been added. Florida upgraded from "Lean McCain" to "Toss-up."

Lean Obama: 63 Electoral Votes

State	EV's	Obama %	McCain %	Margin	# Polls
Colorado	9	46.5%	43.0%	+3.5%	4
Iowa	7	46.0%	39.8%	+6.2%	4
Michigan	17	45.5%	38.8%	+6.7%	5
New Hampshire	4	45.8%	41.0%	+4.8%	4
New Mexico	5	46.8%	40.5%	+6.3%	4
Pennsylvania	21	47.3%	40.3%	+7.0%	4

Toss-up: 108 Electoral Votes

State	EV's	Obama %	McCain %	Margin	# Polls
Indiana	11	43.3%	45.3%	-2.0%	4
Missouri	11	43.8%	45.4%	-1.6%	5
Montana	3	43.3%	46.0%	-2.7%	3
Nevada	5	42.3%	43.0%	-0.7%	4
North Carolina	15	43.6%	44.8%	-1.2%	5
North Dakota	3	43.3%	44.3%	-1.0%	3
Ohio	20	45.3%	44.0%	+1.3%	4
Virginia	13	46.8%	44.8%	+2.0%	4
Florida	27	43.2%	46.0%	-2.8%	6

Lean McCain: 71 Electoral Votes

State	EV's	Obama %	McCain %	Margin	# Polls
Alaska	3	42.0%	47.3%	-5.3%	4
Arizona	10	37.3%	44.0%	-6.7%	4
Georgia	15	41.8%	48.5%	-6.7%	4
Nebraska-02**	1	--	--	-5.0%	0
South Carolina	8	41.3%	45.5%	-4.2%	4
Texas	34	38.8%	46.3%	-7.5%	4

Solid McCain: 86 Electoral Votes

State	EV's	Obama %	McCain %	Margin	# Polls
Alabama	9	35.5%	51.3%	-15.8%	4
Arkansas	6	38.0%	49.0%	-11.0%	4
Idaho	4	39.0%	52.0%	-13.0%	1
Kansas	6	36.8%	51.0%	-14.2%	4
Kentucky	8	36.5%	49.5%	-13.0%	4
Louisiana	9	38.5%	51.3%	-12.8%	4
Mississippi	6	42.0%	52.0%	-10.0%	4
Nebraska-AL**	2	36.0%	52.0%	-16.0%	4
Nebraska-01**	1	--	--	-10.0%	0
Nebraska-03**	1	--	--	-34.0%	0
Oklahoma	7	32.5%	53.3%	-20.8%	2
South Dakota	3	38.8%	47.5%	-8.7%	3
Tennessee	11	34.8%	50.8%	-16.0%	4
Utah	5	32.0%	55.3%	-23.3%	4
West Virginia	5	36.0%	49.0%	-13.0%	2
Wyoming	3	37.5%	53.5%	-16.0%	2

* Maine four electoral votes are awarded as follows: two for the statewide winner, and one for the winner of each congressional district. ME-01 is about 3.5% more Democratic than the state as a whole, while ME-02 is about 3.5% less Democratic than the state as a whole.

** Nebraska's five electoral votes are awarded as follows: two for the statewide winner, and one for the winner of each congressional district. NE-01 is about 6.0% more Democratic than the state as a whole, NE-02 is about 11.0% more Democratic than the state as a whole, and NE-03 is about 18.0% less Democratic than the state as a whole.

Methodology
I will update at least once every day between now and November 4th. The methodology is simple and straightforward.

1. For each state, take the last four polls conducted for the state, and average them.
   
2. If more than four polls were conducted in the state over the previous thirty days, all polls conducted during that time period are included in the averages.
   
3. If polling dates overlap, and make it difficult to determine which polls were the four most recent, include all of the overlapping polls.
   
4. No polling firm discrimination whatsoever. Polls are never excluded because the organization has a bad or partisan reputation. Also, if a polling firm has conducted more than one of the most recent four polls, all of the polls from that organization are included.

As we move closer to the election and more data becomes available, both the time frames for polls included in the averages will decrease and the definition of a "solid" lead will eventually drop to 7.0%.