The US presidential election campaign is entering its final weekend, with polls showing Donald Trump and Kamala Harris in a seemingly permanent deadlock and few clues as to which of them will prevail on Tuesday.

At the end of another unruly week that started with Trump’s racially charged rally at New York’s Madison Square Garden and was punctuated by celebrity endorsements, misogynistic comments and insults about the “garbage” being razed left and right made, the Guardian’s 10-day polling average showed little change from seven days earlier, with voters’ loyalty to their chosen candidate appearing relatively impervious to campaign events, however seismic.

Nationally, Harris, the Democratic nominee, has a one-point lead, 48% to 47%, over her Republican opponent, virtually identical to last week. Such an advantage fits well with the margin of error of most polls.

The battlegrounds are also still in a dead heat. The candidates are evenly divided at 48% in Pennsylvania, which is often seen as the most important swing state because it has the most electoral votes (19). Harris has a single lead in the two other blue wall states, Michigan and Wisconsin, while Trump is marginally ahead in the Sun belt: up 1% in North Carolina and 2% in Georgia and Arizona. In Nevada, his average lead in the polls is less than a percentage point.

The latest polls took place against the backdrop of unprecedented levels of early voting in multiple states, where some 65 million Americans had already cast ballots as of Friday.

It is notoriously difficult to predict anything about the future results of early voting, although about 58% of early voters in Pennsylvania aged 65 or older were registered Democrats, Politico reported, compared to 35% from the same cohort who were registered Republicans; the two main parties have about the same number of registered voters in the state among older adults. About 53% of the population voted for Trump in Pennsylvania in 2020, even though he lost the state to Joe Biden.

Trump, unlike four years ago, has encouraged his supporters to vote early. Democrats turning out in larger numbers could be a positive indicator for them in an uncertain state where commentators have predicted turnout will be key to the outcome. Democratic strategists have claimed they have a 10% to 20% lead in senior voter turnout in the three blue wall states.

But in a fragmented political landscape with threats of retaliation from Trump, accusations of fascism and racism from Harris, and warnings that democracy itself is on the ballot, the bigger picture — that uniformity, over time — has seasoned observers at their limits. scratched. heads.

The survey analytics site FiveThirtyEight’s simulator — based on a collection of national and state data — predicted Friday morning that Trump would win 53 times out of 100, compared to 47 times for Harris, again similar to a week earlier.

In a late burst of positive news for Harris, a Marist poll on Friday raised the possibility that she could break the deadlock, showing her leading Trump by 3% in Michigan and Wisconsin and 2% in Pennsylvania. Winning all three states likely represents Harris’ clearest path to the 270 Electoral College votes needed to win the White House. But the results were within the study’s margins of error.

This near-monolithic picture, which emerges from multiple polls, has led some analysts to suspect that pollsters were “herding” around state poll averages by pollsters wary of being proven wrong for a third time in a row , after significantly underestimating Trump’s support in 2016 and 2020.

Josh Clinton, a professor of politics at Vanderbilt University, and John Lapinski, the network’s elections director, wondered on NBC’s website whether the tie reflected not the feelings of voters but rather risk-averse decision-making by pollsters. Some, they suggested, may be wary of findings that indicate unusually large leads for one candidate and introduce corrective weighting.

Of the last 321 battleground polls, 124 — nearly 40% — showed margins of one point or less, the pair wrote. Pennsylvania was the most “troubling” case, with 20 of 59 polls showing exact parity, while another 26 showed margins of less than 1%.

This indicated “not just an astonishingly tight race, but an impossibly tight race,” Clinton and Lapinski said.

Large numbers of surveys are expected to yield a greater diversity of opinions, even in close elections, due to the randomness inherent in polls. The lack of such variation suggests that pollsters are adjusting “weird” margins of 5% or more, Clinton and Lapinski argued — or the next second possibility, which they considered more likely.

“Some of the tools pollsters are using in 2024 to address the 2020 election problems, such as weighting by partisanship, past voting, or other factors, could smooth out the gaps and reduce the variation in reported poll numbers,” they write .

Both explanations “raise the possibility that the outcome of the election could be unexpectedly different from the razor-sharp narrative that the cluster of state polls and the polling averages suggest,” she added.

Amid the uncertainty, one thing is certain: As close as pollsters have depicted the battle in recent weeks, as Harris and Trump face off in the final days of the most consequential U.S. election in decades, something has to be done.