Sunday, May 11, 2008 at 11:35 pm by Darryl
Poll Analysis: Obama Gains Ground Against McCain
| Obama | McCain |
| 18.6% probability of winning | 80.3% probability of winning |
| Mean of 250 electoral votes | Mean of 288 electoral votes |
Yesterday Sen. Barack Obama had an 8.6% chance of beating Sen. John McCain in a general election held now. Today there was a new Michigan poll released.
In fact, the Michigan poll hurts Obama a little bit. Now, instead of winning the state with a probability of 72.4% (from an older poll), he now only wins with a probability of 40.0%. There is also an older North Carolina poll that expires that drops Obama’s chances in that state from 5.2% to 1.5%. But, what trumps these two changes is that an old Florida poll expires, increasing Obama’s chances in Florida from a probability of 2.5% to 31.9%. The net result is that Obama’s chances in a general election have doubled, although he still remains well behind McCain.
Today, after 10,000 simulated elections, Obama wins 1,860 times (plus he gets the 109 ties), and McCain wins 8,031 times. Obama has a 19.7% (18.6% plus 1.1% for ties) probability of winning a general election held today, and McCain has a 80.3% probability of winning.
The long term trends in this race can be seen from a series of elections simulated every 7 days using polls from 11 Sep 2007 to 11 May 2008, and including polls from the preceding 1 month (FAQ).
Obama has, at best, held steady since late March.
Here is the distribution of electoral votes [FAQ] from the simulations for the current time period:
- 10000 simulations: Obama wins 18.6%, McCain wins 80.3%.
- Average ( SE) EC votes for Obama: 249.9 ( 19.6)
- Average (SE) EC votes for McCain: 288.1 ( 19.6)
- Median (95% CI) EC votes for Obama: 247 (216, 290)
- Median (95% CI) EC votes for McCain: 291 (248, 322)
| State | EC Votes | # polls | Total Votes | % Obama | % McCain | Obama %wins | McCain %wins |
|---|---|---|---|---|---|---|---|
| Alabama | 9 | 2 | 1331 | 37.1 | 62.9 | 0.0 | 100.0 |
| Alaska | 3 | 1* | 455 | 47.3 | 52.7 | 11.1 | 88.9 |
| Arizona | 10 | 1 | 490 | 44.7 | 55.3 | 1.5 | 98.5 |
| Arkansas | 6 | 1* | 445 | 33.7 | 66.3 | 0.0 | 100.0 |
| California | 55 | 2 | 933 | 53.8 | 46.2 | 99.4 | 0.6 |
| Colorado | 9 | 1 | 445 | 51.7 | 48.3 | 77.4 | 22.6 |
| Connecticut | 7 | 1* | 1476 | 59.8 | 40.2 | 100.0 | 0.0 |
| Delaware | 3 | 1* | 553 | 55.0 | 45.0 | 98.7 | 1.3 |
| D.C. | 3 | 0 | (100) | (0) | |||
| Florida | 27 | 1 | 1228 | 49.4 | 50.6 | 31.9 | 68.1 |
| Georgia | 15 | 1 | 460 | 42.4 | 57.6 | 0.1 | 99.9 |
| Hawaii | 4 | 1* | 546 | 66.3 | 33.7 | 100.0 | 0.0 |
| Idaho | 4 | 1* | 553 | 42.9 | 57.1 | 0.0 | 100.0 |
| Illinois | 21 | 1* | 546 | 65.9 | 34.1 | 100.0 | 0.0 |
| Indiana | 11 | 4 | 3421 | 48.8 | 51.2 | 6.9 | 93.1 |
| Iowa | 7 | 2 | 1043 | 54.2 | 45.8 | 99.9 | 0.1 |
| Kansas | 6 | 1 | 470 | 40.6 | 59.4 | 0.0 | 100.0 |
| Kentucky | 8 | 1 | 495 | 31.5 | 68.5 | 0.0 | 100.0 |
| Louisiana | 9 | 1* | 465 | 44.1 | 55.9 | 0.9 | 99.1 |
| Maine | 4 | 1* | 440 | 55.7 | 44.3 | 98.7 | 1.3 |
| Maryland | 10 | 1* | 577 | 57.0 | 43.0 | 99.9 | 0.1 |
| Massachusetts | 12 | 2 | 963 | 53.7 | 46.3 | 99.4 | 0.6 |
| Michigan | 17 | 1 | 445 | 49.4 | 50.6 | 40.0 | 60.0 |
| Minnesota | 10 | 2 | 942 | 55.4 | 44.6 | 100.0 | 0.0 |
| Mississippi | 6 | 1* | 591 | 43.1 | 56.9 | 0.0 | 100.0 |
| Missouri | 11 | 2 | 939 | 46.1 | 53.9 | 0.5 | 99.5 |
| Montana | 3 | 1* | 455 | 47.3 | 52.7 | 10.8 | 89.2 |
| Nebraska | 5 | 1* | 542 | 48.3 | 51.7 | 20.4 | 79.6 |
| Nevada | 5 | 1 | 455 | 47.3 | 52.7 | 11.1 | 88.9 |
| New Hampshire | 4 | 2 | 874 | 47.6 | 52.4 | 8.5 | 91.5 |
| New Jersey | 15 | 1 | 707 | 63.6 | 36.4 | 100.0 | 0.0 |
| New Mexico | 5 | 1 | 461 | 46.9 | 53.1 | 8.3 | 91.7 |
| New York | 31 | 4 | 2516 | 55.9 | 44.1 | 100.0 | 0.0 |
| North Carolina | 15 | 1 | 546 | 45.1 | 54.9 | 1.5 | 98.5 |
| North Dakota | 3 | 1* | 218 | 46.3 | 53.7 | 13.2 | 86.8 |
| Ohio | 20 | 2 | 1443 | 49.2 | 50.8 | 23.7 | 76.3 |
| Oklahoma | 7 | 1* | 569 | 40.1 | 59.9 | 0.0 | 100.0 |
| Oregon | 7 | 2 | 960 | 55.9 | 44.1 | 100.0 | 0.0 |
| Pennsylvania | 21 | 4 | 3817 | 48.9 | 51.1 | 7.1 | 92.9 |
| Rhode Island | 4 | 1* | 572 | 58.2 | 41.8 | 100.0 | 0.0 |
| South Carolina | 8 | 1* | 554 | 48.4 | 51.6 | 20.3 | 79.7 |
| South Dakota | 3 | 1* | 221 | 39.8 | 60.2 | 0.2 | 99.9 |
| Tennessee | 11 | 1* | 450 | 42.2 | 57.8 | 0.1 | 99.9 |
| Texas | 34 | 2 | 1001 | 44.9 | 55.1 | 0.0 | 100.0 |
| Utah | 5 | 1* | 541 | 43.8 | 56.2 | 0.4 | 99.6 |
| Vermont | 3 | 1* | 576 | 68.4 | 31.6 | 100.0 | 0.0 |
| Virginia | 13 | 1 | 495 | 45.9 | 54.1 | 3.3 | 96.7 |
| Washington | 11 | 1 | 590 | 56.9 | 43.1 | 99.9 | 0.1 |
| West Virginia | 5 | 1* | 540 | 39.8 | 60.2 | 0.0 | 100.0 |
| Wisconsin | 10 | 3 | 1422 | 51.0 | 49.0 | 79.9 | 20.1 |
| Wyoming | 3 | 1* | 508 | 39.4 | 60.6 | 0.0 | 100.0 |
* denotes that an older poll was used
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.
