美國大選民調：哈里斯還是川普誰領先？

On November 5, voters in the United States will head to the polls to select their next president. This election is particularly significant as it presents the possibility of Kamala Harris becoming the first female president or Donald Trump securing a second term in office. Initially, this election was expected to be a rematch of the 2020 election, but the dynamics shifted in July when President Joe Biden suspended his campaign and endorsed Vice-President Kamala Harris. As the election day draws near, the central question remains: who will emerge victorious? Since Kamala Harris announced her candidacy at the end of July, she has consistently maintained a slight lead over Donald Trump in national polling averages. By the end of August, she had built a lead of nearly four percentage points, following a surge in her polling numbers during the initial weeks of her campaign. However, since early September, the polling figures have stabilized, even after the candidates faced off in their only debate on September 10, which attracted nearly 70 million viewers. The poll tracker chart illustrates how little the race has shifted nationally in recent weeks, with trend lines indicating averages and individual poll results represented by dots for each candidate. While national polls serve as a useful indicator of a candidate's popularity across the country, they do not necessarily provide an accurate prediction of the election outcome. This is due to the United States' electoral college system, where each state is allocated a number of votes roughly proportional to its population. A total of 538 electoral college votes are available, and a candidate must secure at least 270 to win. Although there are 50 states in the U. S. , most tend to consistently vote for the same party, meaning that only a handful of states, known as battleground states or swing states, will ultimately determine the election's outcome. Currently, the polling averages indicate a tight race in the seven battleground states for this election, with neither candidate holding a decisive lead in any of them. Analyzing the trends since Harris entered the race reveals some differences among the states, but it is essential to recognize that there are fewer state polls compared to national polls, resulting in less data to analyze. Additionally, every poll carries a margin of error, meaning the actual numbers could be higher or lower. In states like Arizona, Georgia, and North Carolina, the lead has shifted between candidates several times since early August, with Trump currently holding a slight advantage. Conversely, in Nevada, Harris is slightly ahead at this moment. In the remaining three battleground states—Michigan, Pennsylvania, and Wisconsin—Harris has maintained a lead since August, sometimes by two or three points, but recent days have seen the polls tighten considerably. These three states were previously strongholds for the Democratic Party before Trump flipped them in 2016. Biden managed to reclaim them in 2020, and if Harris can do the same, she will be well-positioned to win the election. Notably, on the day Biden exited the race, he was trailing Trump by nearly five percentage points on average across the seven swing states. Pennsylvania is particularly crucial for both campaigns, as it has the highest number of electoral votes among the battleground states, making it easier to reach the necessary 270 votes. The averages presented in the graphics are compiled by 538, a part of the American news network ABC News. To create these averages, 538 aggregates data from individual polls conducted both nationally and in battleground states by various polling companies. As part of their quality control, 538 only includes polls from companies that adhere to specific criteria, such as transparency regarding the number of respondents, the timing of the poll, and the methodology used (telephone calls, text messages, online surveys, etc. ). It is important to consider whether we can trust the polls. Currently, the polling data suggests that Kamala Harris and Donald Trump are within a few percentage points of each other in all swing states, making it challenging to predict a clear winner. Polls have historically underestimated support for Trump in both 2016 and 2020. Polling companies are working to address this issue in various ways, including adjusting their methods to better reflect the composition of the voting population. However, these adjustments are complex, and pollsters must still make educated guesses about factors such as voter turnout on November 5.