### Uncertainty Looms as Polling Errors Could Sway 2024 Presidential Election Outcome

As the 2024 presidential election approaches, both Vice President Kamala Harris and former President Donald Trump find themselves in a tightly contested race. However, uncertainty remains over how accurate current polling is, raising significant questions about the potential outcome.

Recent history provides a cautionary tale. In 2020, polls suggested a clear victory for now-President Joe Biden, but they overestimated his lead by about 4 percentage points in key battleground states. This discrepancy resulted in a narrower victory than expected. This polling error echoes the 2016 election, where Trump outperformed expectations in Michigan, Pennsylvania, and Wisconsin, leading to an unexpected Electoral College win.

Looking ahead to 2024, polling averages indicate that the margin between Harris and Trump is within 4 points in seven critical states: Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania, and Wisconsin. Should the polling error of 2020 repeat, Trump could secure all seven swing states, totaling 312 Electoral College votes. Conversely, if the polls overestimate Trump by 4 points, Harris could win these states and accumulate 319 Electoral College votes.

As of October 30th, election forecasting models gave Trump a 52% chance of winning the White House, while Harris stood at 48%. These models use historical polling error data to simulate potential outcomes, considering that battlefield states tend to have varying degrees of polling inaccuracies. The model estimates an average polling error of 3.8 points in competitive states, which is similar to the 2020 polling error but could occur in either candidate's favor this time around.

Interestingly, the probability of polling errors smaller than 2 points is just 33%, meaning that even slight deviations from predicted outcomes in these seven swing states could significantly impact the election results. According to simulations, there is a 60% chance that either Harris or Trump will secure over 300 Electoral College votes, creating a scenario that could be seen as a blowout given the modern electoral landscape.

Accuracy remains a significant concern in polling. Although there are fewer polls from firms with a history of overestimating Democratic performance, difficulties in reaching voters, particularly Trump's supporters, persist. This forces pollsters to rely heavily on weighting and modeling to estimate voter sentiment accurately. These methodologies carry inherent errors, especially since it is challenging to predict the exact composition of the electorate.

Ultimately, election forecasting models, like those of 538, serve to illustrate the probable range of outcomes if polls are inaccurate. While it is clear that both Harris and Trump have nearly equal chances of winning, the exact election margin remains hard to predict and could potentially be wider than anticipated.

In this final week before the election, the inherent uncertainties in polling should remind us that a wide range of Electoral College outcomes is possible, making the race far less predictable than it might initially appear.