Wisconsin is considered one of the most important swing states in this election. According to Nate Silver's presidential election forecast, Wisconsin currently (as of September 18th) has a 13% chance of being the tipping point state, with Harris having a 81,0% chance of winning the election if she wins WI and Trump a 90.7% chance. According to the RCP average from August 23rd to September 16th, Harris currently leads by 1.1% in statewide polls. However, both in 2016 and 2020 RCP's state polling for Wisconsin was off by a large margin (6.5% and 6.0% respectively) in favor of the Republican candidate.
This question is about the error in polling for the 2024 US presidential election in the state of Wisconsin. It concerns the margin between the Democrat and Republican candidates and not between specific candidates like Harris or Trump.
The error is the difference in margin between Democrats and Repuplicans according to RCP (https://www.realclearpolling.com/polls/president/general/2024/wisconsin/trump-vs-harris) data on November 4th, versus the final results according to the Wikipedia page of the election. An error in favor of a candidate means that the candidate does better than polls predict. For example if polls give Harris a 1% lead but Trump wins by 1.5%, this question resolves to [2%-3%) in Republican's favor. This is similar to https://manifold.markets/Weezing/what-will-be-the-polling-error-in-2 but only for the state of Wisconsin and not the whole of the US.