|99.0% probability of winning||1.0% probability of winning|
|Mean of 321 electoral votes||Mean of 217 electoral votes|
[Note: See update at the end of the post]
Last week’s analysis of state head-to-head polls showed President Barack Obama leading Mitt Romney, 327 to 211 electoral votes and with a 99.6% probability of winning an election held then. With 18 new state head-to-head polls weighing in on the contest, Mitt Romney has gained a little more. Here are the polls:
Let’s get New Jersey and New York out of the way. They both have double digit leads for Obama.
Obama takes the latest Florida poll (+4.5%), giving him three of the five current polls, and a 62% probability of taking the state at this point.
In New Mexico Obama slips from +11 in the previous poll to a more moderate +5%. Even though a Romney victory at this point still seems unlikely, there is some hint at a softening of support for Obama:
Three polls in Michigan display remarkable heterogeneity. Obama takes one by double digits, one by single digits, and Romney takes one with a +1. The overall trend still looks more favorable for Obama:
Obama gets a +6.2% in Minnesota which actually seems weak. But the graph of polls does not really indicate any radical change in support for Obama over the long run:
Nevada continues to trend Obama, with a +4% and a +6%.
North Carolina gives Obama a slim +1% lead over Romney, but Romney leads in three of the five current polls. At this point, Romney would take the state with 67% probability.
Obama gets a small +2% lead in the Ohio poll. Obama now leads in four consecutive polls for the state, dating back to early June.
Pennsylvania goes +4 and +6 for Obama in two new polls. He leads in all three current polls and would be expected to win the state with a 98.8% probability.
Two new Virginia polls suggest a very tight race. Obama leads Romney by +1% in one and the other is a tie. The five current polls give Obama a slight edge and a 58% probability in an election held now.
In Wisconsin, the latest poll goes +7% for Obama. Obama leads by about the same amount in all three current polls.
Here in Washington Obama is up by +8.7% over Romney. The longer trend strongly hints at an Obama victory here:
After 100,000 simulated elections, Obama wins 99,012 times and Romney wins 988 times (including the 179 ties). Obama receives (on average) 321 (-6) to Romney’s 217 (+6) electoral votes. Obama has a 99.0% (-0.6%) probability of winning and Romney has a 1.0% (+0.6%) probability of winning an election held now.
Here is the distribution of electoral votes [FAQ] from the simulations:
Ten most probable electoral vote outcomes for Obama:
- 341 electoral votes with a 2.57% probability
- 328 electoral votes with a 2.46% probability
- 342 electoral votes with a 2.16% probability
- 324 electoral votes with a 2.16% probability
- 329 electoral votes with a 2.05% probability
- 323 electoral votes with a 2.03% probability
- 319 electoral votes with a 1.92% probability
- 312 electoral votes with a 1.90% probability
- 314 electoral votes with a 1.79% probability
- 310 electoral votes with a 1.77% probability
After 100,000 simulations:
- Obama wins 99.0%, Romney wins 1.0%.
- Average (SE) EC votes for Obama: 321.1 (21.9)
- Average (SE) EC votes for Romney: 216.9 (21.9)
- Median (95% CI) EC votes for Obama: 323 (277, 360)
- Median (95% CI) EC votes for Romney: 215 (178, 261)
Each column of this table shows the electoral vote total aggregated by different criteria for the probability of winning a state (Safe=100%, Strong=90%+, Leans=60%+, Weak=50%+):
|Threshold||Safe||+ Strong||+ Leans||+ Weak|
This table summarizes results by state. Click on the poll count to see the individual polls included for the state.
|8||4||Votes||polls||Votes||Obama||Romney||% wins||% wins|
* An older poll was used (i.e. no recent polls exist).
Details of the methods are given in the FAQ.
Update: Sam Minter points out that I reversed the numbers for Obama and Romney on the Civitas NC poll. It should be Romney +1. So Romney takes four of the five current NC polls and probably has something closer to 70% or 80% probability of winning the state at this point.
The most recent analysis in this match-up can be found from this page.