Friday, August 15, 2008 at 10:26 pm by Darryl
Poll Analysis: Obama Regains a Few on McCain
| Obama | McCain |
| 92.2% probability of winning | 7.8% probability of winning |
| Mean of 304 electoral votes | Mean of 234 electoral votes |
Yesterday’s analysis showed Sen. Barack Obama leading Sen. John McCain by 298 to 240 electoral votes. If an election had been held yesterday, Obama would be expected to have a 90.6% probability of winning.
There were new polls released today in Maine and North Carolina. Now, after 100,000 simulated elections, Obama wins 92,153 times (including the 453 ties), and McCain wins 7,847 times. Obama receives (on average) 304 to McCain’s 234 electoral votes. If an election were held today, Obama would have a 92.2% probability of winning and McCain, a 7.8% probability of winning.
There were four things that, in total, gave Obama a slight advantage. (1) The expiration of a Florida poll that increased Obama’s chances from 7% to 23%. (2) The new Maine poll that replaced an old poll, increasing Obama’s chances from 91% to 99%. (3) The new North Carolina poll that decreased Obama’s chances from 11% to 5% in that state. (4) An expiring Texas poll that bumps Obama’s chances from 0.4% to 7%.
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 15 Dec 2007 to 15 Aug 2008, and including polls from the preceding 21 days (FAQ).
A slight decline from a June peak is evident in Obama’s electoral vote total.
- 100000 simulations: Obama wins 91.7%, McCain wins 7.8%.
- Average ( SE) EC votes for Obama: 303.7 (25.9)
- Average (SE) EC votes for McCain: 234.3 (25.9)
- Median (95% CI) EC votes for Obama: 304 (248, 354)
- Median (95% CI) EC votes for McCain: 234 (184, 290)
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 | 41 | |||
| Strong Obama | 180 | 221 | ||
| Leans Obama | 72 | 72 | 293 | |
| Weak Obama | 11 | 11 | 11 | 304 |
| Weak McCain | 16 | 16 | 16 | 234 |
| Leans McCain | 56 | 56 | 218 | |
| Strong McCain | 136 | 162 | ||
| Safe McCain | 26 |
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 | 2 | 922 | 41.1 | 58.9 | 0.0 | 100.0 | |
| Alaska | 3 | 2 | 790 | 49.4 | 50.6 | 39.5 | 60.5 | |
| Arizona | 10 | 2 | 1395 | 42.3 | 57.7 | 0.0 | 100.0 | |
| Arkansas | 6 | 1* | 455 | 42.9 | 57.1 | 1.6 | 98.4 | |
| California | 55 | 1* | 470 | 55.3 | 44.7 | 95.3 | 4.7 | |
| Colorado | 9 | 2 | 1538 | 51.0 | 49.0 | 71.2 | 28.8 | |
| Connecticut | 7 | 1 | 465 | 57.0 | 43.0 | 98.4 | 1.6 | |
| Delaware | 3 | 1* | 553 | 55.0 | 45.0 | 95.5 | 4.5 | |
| D.C. | 3 | 0 | (100) | (0) | ||||
| Florida | 27 | 4 | 2881 | 49.0 | 51.0 | 22.8 | 77.2 | |
| Georgia | 15 | 1 | 468 | 47.6 | 52.4 | 23.3 | 76.7 | |
| Hawaii | 4 | 1* | 546 | 66.3 | 33.7 | 100.0 | 0.0 | |
| Idaho | 4 | 1 | 450 | 41.1 | 58.9 | 0.5 | 99.5 | |
| Illinois | 21 | 1* | 435 | 57.5 | 42.5 | 98.7 | 1.3 | |
| Indiana | 11 | 1* | 596 | 50.5 | 49.5 | 56.6 | 43.4 | |
| Iowa | 7 | 1 | 465 | 52.7 | 47.3 | 79.2 | 20.8 | |
| Kansas | 6 | 1 | 480 | 42.7 | 57.3 | 1.1 | 98.9 | |
| Kentucky | 8 | 3 | 1582 | 42.9 | 57.1 | 0.0 | 100.0 | |
| Louisiana | 9 | 1* | 440 | 38.6 | 61.4 | 0.0 | 100.0 | |
| Maine | 4 | 1 | 460 | 57.6 | 42.4 | 98.9 | 1.1 | |
| Maryland | 10 | 1* | 577 | 57.0 | 43.0 | 99.3 | 0.7 | |
| Massachusetts | 12 | 2 | 800 | 57.3 | 42.8 | 99.8 | 0.2 | |
| Michigan | 17 | 2 | 1211 | 51.9 | 48.1 | 81.9 | 18.1 | |
| Minnesota | 10 | 1 | 658 | 52.1 | 47.9 | 76.9 | 23.1 | |
| Mississippi | 6 | 1 | 480 | 43.8 | 56.3 | 2.6 | 97.4 | |
| Missouri | 11 | 2 | 1827 | 47.2 | 52.8 | 5.1 | 94.9 | |
| Montana | 3 | 1 | 658 | 50.0 | 50.0 | 50.0 | 50.0 | |
| Nebraska | 5 | 1 | 455 | 39.6 | 60.4 | 0.1 | 99.9 | |
| Nevada | 5 | 1 | 651 | 48.4 | 51.6 | 28.7 | 71.3 | |
| New Hampshire | 4 | 1* | 470 | 52.1 | 47.9 | 74.2 | 25.8 | |
| New Jersey | 15 | 2 | 1791 | 55.2 | 44.8 | 99.9 | 0.1 | |
| New Mexico | 5 | 1* | 644 | 53.3 | 46.7 | 88.6 | 11.4 | |
| New York | 31 | 2 | 1713 | 61.1 | 38.9 | 100.0 | 0.0 | |
| North Carolina | 15 | 4 | 2563 | 47.7 | 52.3 | 5.2 | 94.8 | |
| North Dakota | 3 | 1* | 435 | 48.3 | 51.7 | 30.1 | 69.9 | |
| Ohio | 20 | 1 | 1106 | 51.1 | 48.9 | 70.3 | 29.7 | |
| Oklahoma | 7 | 1* | 600 | 30.0 | 70.0 | 0.0 | 100.0 | |
| Oregon | 7 | 2 | 1055 | 53.3 | 46.7 | 93.4 | 6.6 | |
| Pennsylvania | 21 | 3 | 2779 | 54.5 | 45.5 | 100.0 | 0.0 | |
| Rhode Island | 4 | 1* | 430 | 64.0 | 36.0 | 100.0 | 0.0 | |
| South Carolina | 8 | 1* | 465 | 43.0 | 57.0 | 1.7 | 98.3 | |
| South Dakota | 3 | 1* | 420 | 47.6 | 52.4 | 24.3 | 75.7 | |
| Tennessee | 11 | 1* | 435 | 41.4 | 58.6 | 0.5 | 99.5 | |
| Texas | 34 | 1 | 455 | 45.1 | 54.9 | 7.0 | 93.0 | |
| Utah | 5 | 1* | 425 | 38.8 | 61.2 | 0.1 | 99.9 | |
| Vermont | 3 | 1* | 576 | 68.4 | 31.6 | 100.0 | 0.0 | |
| Virginia | 13 | 3 | 1645 | 49.6 | 50.4 | 41.0 | 59.0 | |
| Washington | 11 | 3 | 1694 | 55.5 | 44.5 | 100.0 | 0.0 | |
| West Virginia | 5 | 1* | 410 | 45.1 | 54.9 | 8.6 | 91.4 | |
| Wisconsin | 10 | 3 | 1679 | 53.3 | 46.7 | 97.6 | 2.4 | |
| Wyoming | 3 | 1* | 465 | 43.0 | 57.0 | 1.6 | 98.4 |
* 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.
