After Joe Biden defeated Donald Trump in both the popular vote and the Electoral College in the 2020 presidential election, the results were contested on many fronts.

In a campaign to overturn the election that became known as the "Big Lie," Trump and ardent supporters such as former New York City Mayor Rudy Giuliani impugned election workers, claimed massive voter fraud and called for recounts in states with relatively close margins.

And then there was the storming of the US Capitol on January 6, 2021, a last-ditch effort to overturn the election by force.

Trump is again the presidential candidate for the Republican Party in 2024. Along with many of his supporters, including his running mate, JD Vance, he continues to repeat the false claims about the 2020 election.

The Trump team has also refused to commit to accepting the outcome of the 2024 election, leading to fears of new upheaval in the US should he not be declared the winner.

A landslide victory for the Democratic nominee, Vice President Kamala Harris, would make significant challenges by mainstream Republicans less likely.

When it comes to accepting defeat, 72% of voters say Harris will accept the results, acknowledge Trump's victory if he wins and concede, according to survey results released by the Washington-based Pew Research Center on October 10.

The same survey found that only 24% think Trump will concede if he loses the election.

But the campaign to reinstall Trump as president started long before the polls, and there have been significant efforts to limit who can participate in this year's election. 

Since 2020, the nonpartisan Voting Rights Lab has recorded more than 700 new election laws across the country. Some of these make voting more accessible; many others, such as reducing polling locations and adding ID requirements, do not. 

States pass bills to purge voting lists

Every state has processes to make sure voter lists are accurate. Part of this means cleaning up these lists by removing names of people who have died, moved or become ineligible to vote.

Since 2021, 32 states have introduced at least 148 bills that would restrict how up-to-date voting lists are, and 11 of these have become law, according to an analysis published in April by Voting Rights Lab.

The analysis detailed efforts to purge people from voting lists around the country, with activist groups and the Republican National Committee filing lawsuits in numerous states to force election officials to remove voters.

Earlier this year, Indiana passed a law requiring election officials to identify non-citizens through Department of Motor Vehicles records, a state agency responsible for vehicle registration and driver's licenses. The new regulation has no safeguards to protect against the removal of people who have become naturalized citizens.

Last year, North Carolina passed a bill also targeting non-citizen voting. This rule uses lists of people excused from jury duty because they self-identified as a non-citizen. But the removal process doesn't have proper checks in place, found the Voting Rights Lab.

Additionally, the Republican National Committee has started an initiative called Protect the Vote. The idea is to find and train 100,000 "poll watchers" to monitor voting locations. 

Swing states in the crosshairs 

The Voting Rights Lab is especially concerned about changes in the swing states of Georgia and North Carolina.

In Georgia, new laws since 2020 have led to mass challenges to voter lists, added ID requirements to postal voting, restricted the use of drop boxes for ballots and caused a jump in ballot rejection rates.

North Carolina now has the strictest rules in the country when it comes to postal voting. New rules require mail voters to include a copy of their ID, plus a notary's signature or the signature of two witnesses.

The state has also given partisan poll watchers more rights. Observers appointed by political parties can take notes, listen to conversations between voters and poll workers and watch any setup and teardown procedures at polling stations.

All of these new possibilities could intimidate voters and make it more difficult for local election officials overseeing the process.

"There is some truth to the fact that Republicans have been working to elect supporters of the 'Big Lie' in 2020 to key election positions in the states," said Dan Mallinson, an associate professor of public policy and administration at Penn State Harrisburg in Pennsylvania.

"They have not always been successful, but there have also been efforts to have supporters pursue lower-level elections positions, too," he added. 

What happens after November 5?

After the election on November 5, all votes will need to be counted. In the past, some polling places took days or weeks to complete these counts.

Then the results need to be certified at the local and state level before being sent to the Electoral College and the US Congress. The closer the results, the likelier a challenge.

"Former President Trump is already laying the rhetorical and legal groundwork to contest the election," said Mallinson. 

Should Trump be declared the winner in states key to the Electoral College, Democrats might adopt some of the strategies used by his campaign. "As Republicans have used rhetoric and litigation to question elections, it makes it easier for Democrats to also do so," said Mallinson.

To allow all this to play out, there are nearly 11 weeks between the election and the certification of the Electoral College vote on January 6, 2025.

What's the worst-case scenario?

If states delay or refuse to certify results, it could lead to chaos, said Mallinson. If a state were to fail to certify its results in time for the Electoral College count, the Republican-controlled US House of Representatives would step in to decide. 

An evenly split Electoral College count would also go to the newly elected House "where each state delegation receives one vote that they must decide how to cast for the president," he added.

Ultimately, the Supreme Court could have the last word, as it did in 2000, when it sided with George W. Bush in the race against Al Gore.

Many hope it doesn't go that far. A situation where any side feels the election is unfair could make working together across party lines harder, and weaken the country.

Overall, 71% of voters view the 2024 campaign as being too negative, while only 19% said the campaign makes them feel proud of their country, according to the Pew Research Center survey.

If voters no longer trust the system or the other side, it could end up dimming a beacon of democracy.

Edited by: M. Gagnon