Not everything will run perfectly on Election Day. Still, US elections are remarkably reliable

WASHINGTON (AP) — On Election Day, some voting lines will likely be long and some precincts may run out of ballots. An election office website could go down temporarily and ballot-counting machines will jam. Or people who help run elections might just act like the humans they are, forgetting their key to a local polling place so it has to open later than scheduled.

These kinds of glitches have occurred throughout the history of U.S. elections. Yet election workers across America have consistently pulled off presidential elections and accurately tallied the results — and there's no reason to believe this year will be any different.

Elections are a foundation of democracy. They also are human exercises that, despite all the laws and rules governing how they should run, can sometimes appear to be messy. They're conducted by election officials and volunteers in thousands of jurisdictions across the United States, from tiny townships to sprawling urban counties with more voters than some states have people.

It's a uniquely American system that, despite its imperfections, reliably produces certified outcomes that stand up to scrutiny. That's true even in an era of misinformation and hyperpartisanship.

“Things will go wrong,” said Jen Easterly, the director of the U.S. Cybersecurity and Infrastructure Security Agency.

None of these will mean the election is tainted or rigged or is being stolen. But Easterly said election offices need to be transparent about the hiccups so they can get ahead of misinformation and attempts to exploit routine problems as a way to undermine confidence in the election results.

"At the end of the day, we need to recognize things will go wrong. They always do," Easterly said. “It will really come down to how state and local election officials communicate about those things going wrong.”

It wasn't that long ago when American voters accepted the results, even if their preferred presidential candidate lost.

Even in 2000, when 104 million votes came down to a 5-to-4 Supreme Court decision that effectively made Republican George W. Bush the president, his opponent, Democrat Al Gore, quickly conceded. The republic moved on peacefully.

Times have changed dramatically since then.

The internet, false claims and a voting public susceptible to conspiratorial theories about widespread voter fraud have changed that. Trust in the system is low, particularly among Republican voters whose perceptions have been shaped by a steady drumbeat of lies about the 2020 election by Donald Trump, the former president who is the Republican nominee on the Nov. 5 ballot.

At his campaign rallies, Trump continues to claim that the only way he can lose is if the other side rigs the election. In fact, it would be virtually impossible for anyone to rig a U.S. presidential race given the decentralized nature of the country's elections, which are run by thousands of municipal or county voting jurisdictions.

What is more likely are simple mistakes and technical mishaps that occur during every election.

“When elections are very close and you have to look under the hood, sometimes you find some problems. Almost always those problems are the result of human error, incompetence — not malfeasance,” said Rick Hasen, an election law expert and professor at the University of California, Los Angeles.

“Both voter fraud and election administrator fraud is currently very rare in the United States. When it does happen, it’s not that hard to catch because of the safeguards in the system.”

Distrust in elections is real and has serious consequences. Lies about the 2020 election being rigged were a catalyst for the Jan. 6, 2021, attack on the Capitol.

This has come despite Trump and his allies losing dozens of court cases aimed at reversing his loss to Democrat Joe Biden. Even a commission Trump created while president to investigate the 2016 election in hopes of identifying widespread voter fraud found none. Special police units established by a few Republican governors came up similarly empty-handed when they searched for widespread fraud during the 2022 midterm elections.

In addition to the court cases, Trump’s own attorney general and reviews, recounts and audits in the presidential battleground states found no evidence of widespread fraud and affirmed Biden’s victory.

That hasn't mattered.

As late as 2023, a sizable portion of Republicans believed Biden was not the legitimately elected, and election conspiracy theories have taken root in Republican-leaning communities.

It would be incorrect to say there is never any fraud associated with elections. But in the 2020 election, an Associated Press investigation in the battleground states where Trump disputed his loss found an amount too small to alter the election. In most cases, it was individuals acting alone, not as part of a grand conspiracy to throw the election.

“The story of the last few decades is that voting systems in the United States are very secure," said Robert Lieberman, a political science professor at Johns Hopkins University.

Basic mistakes, whether human or technical.

In Jackson, Mississippi, a ballot problem was blamed on inexperience and lack of training. In Luzerne County, Pennsylvania, inexperience was again the culprit when polling places ran out of ballots.

Sometimes the envelopes used to return the mailed ballots can create problems. The Pennsylvania Department of State recently announced on X that because of high humidity levels in much of the state, “some voters are finding that their mail-in ballots have the return envelope already sealed." It advised voters to contact their local election office for next steps.

Paper was the culprit in a Maricopa County, Arizona, in 2022 when the ballot printers had problems and caused large backups in voter lines.

One of the major concerns heading into the 2024 presidential election is the high turnover in election offices across the country, in particular in some of the presidential battlegrounds, said Edward B. Foley, a law professor who leads Ohio State University’s election law program.

Before the 2022 midterms, for example, 10 of Nevada's 17 counties had turnover among their clerk or registration positions, which oversee voting.

Threats and harassment from those who believe election conspiracy theories have fueled the attrition. Despite all the training election workers receive, there’s no substitute for the experience of going through a major election cycle.

Many of those who have left had years and even decades of experience. In some cases, they have been replaced by people with little or no experience, and who at times have peddled conspiracy theories.

“If you're looking for something to watch out for and be concerned about," Foley said, "that is one place.”

Associated Press writers Christina A. Cassidy and Ali Swenson contributed to this report.

Read more about how U.S. elections work at Explaining Election 2024, a series from The Associated Press aimed at helping make sense of the American democracy. The AP receives support from several private foundations to enhance its explanatory coverage of elections and democracy. See more about AP’s democracy initiative here. The AP is solely responsible for all content.

FILE - Director of the Cybersecurity and Infrastructure Security Agency (CISA) Jen Easterly speaks to The Associated Press in Washington, Wednesday, Oct. 2, 2024. (AP Photo/Ben Curtis, File)

FILE - People wait to vote in-person at Reed High School in Sparks, Nev., prior to polls closing on Nov. 3, 2020. (AP Photo/Scott Sonner, File)

FILE - A county worker collects a mail-in ballots in a drive-thru mail-in ballot drop off area at the Clark County Election Department, Monday, Nov. 2, 2020, in Las Vegas. (AP Photo/John Locher, File)

FILE - A voter moves to cast her ballot at an electronic counting machine at a polling site at the Brooklyn Museum, Nov. 8, 2022, in the Brooklyn borough of New York. ( AP Photo/John Minchillo, File)

FILE - Director of the U.S. Cybersecurity and Infrastructure Security Agency (CISA) Jen Easterly speaks to The Associated Press in Washington, Wednesday, Oct. 2, 2024. (AP Photo/Ben Curtis, File)

FILE "- I Voted Early" stickers sit in a bucket by the ballot box at the City of Minneapolis early voting center, Thursday, Sept. 19, 2024, in St. Paul, Minn. (AP Photo/Adam Bettcher, File)

FILE - A poll worker talks to a voter before they vote on a paper ballot on Election Day in Atlanta on Tuesday, Nov. 3, 2020. (AP Photo/Brynn Anderson, File)

FILE - A voter fills out their Ohio primary election ballot at a polling location in Knox Presbyterian Church in Cincinnati, Ohio, on Tuesday, March 19, 2024. (AP Photo/Carolyn Kaster, File)

WASHINGTON (AP) — One question will be asked over and over on election night: Who won?

The Associated Press will answer that question for nearly 5,000 contested races across the United States and up and down the ballot, from president and state ballot measures to a variety of local offices.

The AP has compiled vote results and declared winners in elections for more than 170 years, filling what could otherwise be a critical information void of up to a month between Election Day and the official certification of results.

What goes into determining the winners? A careful and thorough analysis of the latest available vote tallies and a variety of other election data, with the ultimate goal of answering this question: Is there any circumstance in which the trailing candidate can catch up? If the answer is no, then the leading candidate has won.

Race calls are based on provable facts, primarily from the AP’s vote count, which is compiled from state and local election offices around the nation.

As more and more ballots are tabulated starting on election night, the AP will monitor the incoming vote at the county level and analyze who is in the lead and what areas the votes are coming from.

At the same time, the AP tries to determine throughout the night how many ballots are uncounted and from what areas. State and local election officials don’t immediately know by election night exactly how many ballots were cast in every contest. Determining how many remain has become more complicated because of the growing number of ballots cast by mail that may arrive after Election Day, which is Nov. 5 this year.

This means there are usually no official and exact tallies of the outstanding vote to rely on once the vote counting gets underway. As a result, the AP estimates the turnout in every race based on several factors and uses that estimate to track how much of the vote has been counted and how much remains.

The AP also tries to determine how ballots counted so far were cast, and the types of vote — such as mail ballots or Election Day in-person — that remain.

That's because the method a voter chooses often speaks to whom they voted for. Since the issue of voting by mail became highly politicized in the 2020 election, most mail votes nationally have been cast by Democratic voters, while most in-person Election Day votes have been cast by Republicans.

In many states, it is possible to know which votes will be counted first from past elections or plans announced by election officials. In some others, votes counted so far are clearly marked by type.

This helps to determine if an early lead is expected to shrink or grow. For example, if a state first counts votes cast in person on Election Day, followed by mail-in votes, that suggests that an early Republican lead in the vote count may narrow as more mail ballots are tabulated. But if the reverse is true and mail ballots are counted first, an early Republican lead could be the first sign of a comfortable victory.

The AP’s analysis to determine the winners is also greatly informed by other election data, especially the long-standing voting trends in a given area. Past election results over time show that states and counties with a long history of lopsided Republican or Democratic victories tend to continue the same voting patterns from one election to the next.

Even in closely contested races, comparing current vote patterns with those in past races can provide important clues.

For example, if a Democratic candidate is performing a few percentage points better across all counties that have reported votes in a state a Democrat previously won by a narrow margin, that could be a sign of a more comfortable Democratic victory. But if the Republican is performing a few percentage points better, that could point to an exceedingly close race or even a flipped result.

Large changes in an area’s voting patterns that differ substantially from statewide trends are certainly possible but tend to take root over a time frame of multiple elections. This helps analysts understand whether one candidate’s lead is an expected result or a sign of tight race. It also helps determine whether the remaining uncounted ballots are from areas that would likely benefit one candidate over another.

Demographic data can also shed light on the vote count. For example, shifts that differ from statewide patterns might be explained by a shift among a specific group, such as Hispanic voters or white voters without college degrees.

Another tool available to the AP’s decision teams is AP VoteCast, a comprehensive, 50-state election survey that provides a detailed snapshot of who voted in an election and what was on their minds when they voted. Data from AP VoteCast makes it possible in some cases to call non-competitive or less competitive races as the polls close or shortly afterward with the initial release of votes.

When considering poll-close calls, the AP will only declare a winner if AP VoteCast data confirms the expected result in that contest based on past vote history and other preelection data.

In almost all cases, races can be called well before 100% of the votes have been counted. The AP’s team of election journalists and analysts will call a race as soon as a clear winner can be determined. That may sound obvious, but it is the guiding principle that drives the organization’s election race-calling process.

The AP’s race calls are not predictions and are not based on speculation. They are declarations based on an analysis of vote results and other election data that one candidate has emerged as the winner and that no other candidate in the race will be able to overtake the winner once all the votes have been counted.

The AP may delay calling a winner if the vote results go against the expected outcome of the contest as indicated by the available election data. In other words, if the vote results show a large lead for one candidate but some combination of the past vote history, demographic data or AP VoteCast data point to a different outcome, the AP would carefully review the vote results before making any determination.

In competitive races, AP analysts may need to wait until additional votes are tallied or to confirm specific information about how many ballots are left to count.

The AP may declare that a race is “too close to call” if a race is so close that there's no clear winner even once all ballots except for provisional and late-arriving absentee ballots have been counted.

Competitive races where votes are actively being tabulated — for example in states that count a large number of voters after election night — might be considered “too early to call.” The “too close to call” designation is not used for these types of races.

The AP may also decide not to call a race if the margin between the top two candidates is less than 0.5 percentage points unless it determines that the margin is wide enough that it could not change in a recount.

AP race calls are never made based on lobbying from campaigns or political parties or announcements made by other news organizations, or on candidate victory speeches. Although it will never call a winner based on a concession speech, in some cases, a concession is the final piece of the puzzle in confirming that there will be no recount in a close race.

Read more about how U.S. elections work at Explaining Election 2024, a series from The Associated Press aimed at helping make sense of the American democracy. The AP receives support from several private foundations to enhance its explanatory coverage of elections and democracy. See more about AP’s democracy initiative here. The AP is solely responsible for all content.

A screen shows a news program website on the U.S. elections as a traders of a foreign exchange dealing company looks on Wednesday, Nov. 4, 2020, in Tokyo. (AP Photo/Eugene Hoshiko)

FILE - In this Feb. 5, 2020, photo Associated Press Washington Bureau Chief Julie Pace, right, looks over a headline with deputy managing editor for operations David Scott in the newsroom at the Associated Press in Washington. (AP Photo/Jenny Kane, File)

FILE - Media organizations set up outside the White House, Friday, Nov. 6, 2020, in Washington. (AP Photo/Evan Vucci, File)