Obama v. McCain

04 Nov 2008

Obama McCain
100.0% probability of winning 0.0% probability of winning
Mean of 364 electoral votes Mean of 174 electoral votes

Electoral College Map

Washington Oregon Idaho Montana Wyoming North Dakota South Dakota Minnesota Wisconsin Iowa Illinios Indiana Colorado Utah New Mexico Texas Nebraska Oklahoma Kansas Nevada California Arizona Missouri Arkansas Louisiana Mississippi Alabama Tennessee Georgia Kentucky Ohio Michigan Pennsylvania West Virginia Virginia Hawaii Alaska North Carolina South Carolina Florida New York Vermont New Hampshire Maine Massachusetts Rhode Island Connecticut New Jersey Delaware Maryland District of Columbia

Electoral College Map

Washington Oregon Idaho Montana Wyoming North Dakota South Dakota Minnesota Wisconsin Iowa Illinios Indiana Colorado Utah New Mexico Texas Nebraska Oklahoma Kansas Nevada California Arizona Missouri Arkansas Louisiana Mississippi Alabama Tennessee Georgia Kentucky Ohio Michigan Pennsylvania West Virginia Virginia Hawaii Alaska North Carolina South Carolina Florida New York Vermont New Hampshire Maine Massachusetts Rhode Island Connecticut New Jersey Delaware Maryland District of Columbia

Yesterday’s analysis showed Sen. Barack Obama leading Sen. John McCain by 363 to 175 electoral votes (on average). On election day, we have eleven new polls in ten states released. Obama improves slightly.

Today, after 100,000 simulated elections, Obama wins all 100,000 times—this mean that Obama is predicted to win the election with near-100% certainty today.

Obama receives (on average) 364 to McCain’s 174 electoral votes. The most likely outcome for this election, however, is an Obama victory with 367 electoral votes (see the list below).

This analysis uses a one-week window for polls to include. But, there have been a couple of states in which the window may be too wide (that is, there were large movements over the last couple of days). Specifically, North Carolina is painted blue now, but may well go for McCain, given the changes seen over the last couple of days.

Missouri is another example. There have been four ties in the last four polls. Obama led before that, then another tie, then two McCain leads in the most recent polls. A narrower poll window would have given the state to Obama. A really narrow window would have had the state tied. Time will tell….

Here is the distribution of electoral votes [FAQ] from the simulations:

The long term trends in this race can be seen from a series of elections simulated every seven days using polls from 04 Mar 2008 to 04 Nov 2008, and including polls from the preceding seven days (FAQ).

Here are the ten most probable electoral vote outcomes for Obama:

  • 367 electoral votes with a 5.4% probability
  • 364 electoral votes with a 4.3% probability
  • 356 electoral votes with a 3.8% probability
  • 353 electoral votes with a 3.8% probability
  • 373 electoral votes with a 3.2% probability
  • 349 electoral votes with a 3.0% probability
  • 352 electoral votes with a 2.9% probability
  • 370 electoral votes with a 2.8% probability
  • 375 electoral votes with a 2.7% probability
  • 362 electoral votes with a 2.7% probability

Outcomes:

  • 100000 simulations: Obama wins 100.0%, McCain wins 0.0%.
  • Average ( SE) EC votes for Obama: 363.8 (18.3)
  • Average (SE) EC votes for McCain: 174.2 (18.3)
  • Median (95% CI) EC votes for Obama: 364 (326, 401)
  • Median (95% CI) EC votes for McCain: 174 (137, 212)

This table shows the electoral vote total for different criteria for the probability of winning a state (Safe=100%, Strong=90%+, Leans=60%+, Weak=50%+):

Threshold Safe + Strong + Leans + Weak
Safe Obama 233
Strong Obama 78 311
Leans Obama 42 42 353
Weak Obama 0 0 0 353
Weak McCain 14 14 14 185
Leans McCain 39 39 171
Strong McCain 82 132
Safe McCain 50

This table summarizes the results by state. Click on the poll number to see the individual polls included for a state.

EC # Total % % Obama McCain
State ‘04 Votes polls Votes Obama McCain % wins % wins
Alabama 9 1* 630 37.1 62.9 0.0 100.0
Alaska 3 4 2031 43.1 56.9 0.0 100.0
Arizona 10 2 1146 48.7 51.3 26.2 73.8
Arkansas 6 1 570 46.3 53.7 10.5 89.5
California 55 1 611 62.5 37.5 100.0 0.0
Colorado 9 4 4125 53.8 46.2 100.0 0.0
Connecticut 7 1* 437 64.3 35.7 100.0 0.0
Delaware 3 1* 631 65.6 34.4 100.0 0.0
D.C. 3 1* 570 86.3 13.7 100.0 0.0
Florida 27 11 10063 50.7 49.3 84.8 15.2
Georgia 15 6 4303 48.2 51.8 4.8 95.2
Hawaii 4 1* 475 71.6 28.4 100.0 0.0
Idaho 4 1* 438 36.8 63.2 0.0 100.0
Illinois 21 1 490 61.2 38.8 100.0 0.0
Indiana 11 6 5572 49.6 50.4 32.6 67.4
Iowa 7 3 1918 58.4 41.6 100.0 0.0
Kansas 6 1* 595 39.0 61.0 0.0 100.0
Kentucky 8 4 2415 42.6 57.4 0.0 100.0
Louisiana 9 1* 394 48.2 51.8 30.3 69.7
Maine 4 2 1142 58.8 41.2 100.0 0.0
Maryland 10 1* 485 61.9 38.1 100.0 0.0
Massachusetts 12 1* 625 58.9 41.1 99.9 0.1
Michigan 17 5 4028 57.1 42.9 100.0 0.0
Minnesota 10 5 3586 56.1 43.9 100.0 0.0
Mississippi 6 1 558 43.0 57.0 1.1 98.9
Missouri 11 8 5853 49.9 50.1 43.4 56.6
Montana 3 4 4199 49.6 50.4 35.4 64.6
Nebraska 5 1* 465 39.8 60.2 0.2 99.8
Nevada 5 5 3498 53.1 46.9 99.6 0.4
New Hampshire 4 7 4260 55.5 44.5 100.0 0.0
New Jersey 15 3 1802 58.5 41.5 100.0 0.0
New Mexico 5 4 3274 56.3 43.7 100.0 0.0
New York 31 1* 601 65.2 34.8 100.0 0.0
North Carolina 15 12 9305 50.4 49.6 68.6 31.4
North Dakota 3 1 465 49.5 50.5 43.3 56.7
Ohio 20 9 8469 51.4 48.6 96.7 3.3
Oklahoma 7 1 576 35.1 64.9 0.0 100.0
Oregon 7 4 3119 58.1 41.9 100.0 0.0
Pennsylvania 21 12 9803 54.1 45.9 100.0 0.0
Rhode Island 4 1* 564 59.2 40.8 100.0 0.0
South Carolina 8 1 628 45.9 54.1 7.2 92.8
South Dakota 3 1 485 45.4 54.6 8.1 91.9
Tennessee 11 1* 552 41.3 58.7 0.2 99.8
Texas 34 1* 490 44.9 55.1 6.1 93.9
Utah 5 1* 1073 36.0 64.0 0.0 100.0
Vermont 3 1* 372 61.3 38.7 99.8 0.2
Virginia 13 7 5553 52.6 47.4 99.8 0.2
Washington 11 3 1744 57.8 42.2 100.0 0.0
West Virginia 5 2 2634 43.5 56.5 0.0 100.0
Wisconsin 10 2 1371 57.7 42.3 100.0 0.0
Wyoming 3 1 485 37.1 62.9 0.0 100.0

* An older poll was used (i.e. no recent polls exist).

Details of the methods are given in the FAQ.

The most recent analysis in this and other match-ups can be found from this page.

(Permanent link to this analysis.)

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