My previous analysis of the Biden-Trump head-to-head polls was way back in early June, in part because the dynamics of the race didn’t seem to be changing much. Trump is slowly slipping in the polls, as the COVID-19 epidemic worsens in the U.S., as Trump resists movements for police reforms, and as we learn bizarre things like Trump not responding to Russian bounties on American soldiers in Afghanistan.
After 100,000 simulated elections, the results are not surprising. Biden wins 100,000 times and Trump wins 0 times. Biden received (on average) 375 to Trump’s 163 electoral votes. In an election held now, Biden would have a greater than 99.9% probability of winning and Trump would have a less than 0.1% probability of winning.
Basically, if the election was today, Biden would win in a landslide.
Trump has a serious electoral college problem. Many swing states are now trending strongly for Biden, including Florida, Michigan, and Wisconsin. Other swing states are pretty solidly in Biden’s camp, like Arizona, Colorado, New Hampshire, New Mexico, North Carolina, Pennsylvania, and Virginia. Even Ohio trends slightly toward Biden. Iowa and Texas are in toss-up territory, but leaning slightly toward Trump. Remarkable!
The trend over the past couple months are clear from from a series of elections simulated every seven days using polls from Jul 2019 to the present, and, at each point in time, including polls from the preceding month (FAQ).
There is, of course, plenty of time to turn this trend around. Still, Trump’s bizarre and impulsive behavior will make doing that very difficult.
Back to the analysis for what would happen in an election today, the ten most probable electoral vote outcomes for Biden (full distribution here) are:
- 375 electoral votes with a 5.26% probability
- 369 electoral votes with a 4.68% probability
- 351 electoral votes with a 3.62% probability
- 357 electoral votes with a 3.61% probability
- 374 electoral votes with a 3.21% probability
- 368 electoral votes with a 2.87% probability
- 413 electoral votes with a 2.57% probability
- 363 electoral votes with a 2.49% probability
- 356 electoral votes with a 2.38% probability
- 378 electoral votes with a 2.24% probability
Here is the entire distribution of electoral votes [FAQ] from the simulations:
After 100,000 simulations:
- Biden wins greater than 99.9%, Trump wins less than 0.1%.
- Average (SE) EC votes for Biden: 374.6 (22.1)
- Average (SE) EC votes for Trump: 163.4 (22.1)
- Median (95% CI) EC votes for Biden: 372 (336, 418)
- Median (95% CI) EC votes for Trump: 166 (120, 202)
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.
|6||2||Votes||polls||Votes||Biden||Trump||% wins||% wins|
* An older poll was used (i.e. no recent polls exist).
Details of the methods are given in the FAQ.