WASHINGTON (AP) — This presidential election, the first since the Jan. 6, 2021, insurrection at the Capitol, will be a stress test of the new systems and guardrails that Congress put in place to ensure America's long tradition of the peaceful transfer of presidential power.

As Republican Donald Trump and Democrat Kamala Harris race toward the finish, pro-democracy advocates and elected officials are preparing for a volatile period in the aftermath of Election Day, as legal challenges are filed, bad actors spread misinformation and voters wait for Congress to affirm the results.

"One of the unusual characteristics of this election is that so much of the potential danger and so many of the attacks on the election system are focused on the post-election period," said Wendy Weiser, vice president for democracy at the nonpartisan Brennan Center for Justice.

After the Jan. 6 attack, Congress set out to shore up the process and prevent a repeat of that unprecedented period when Trump, joined by some GOP allies in Congress, refused to concede defeat to President Joe Biden. Trump spent months pushing dozens of failed legal cases before sending his supporters to the U.S. Capitol, where they disrupted the electoral count with a bloody riot. He faces a federal indictment for the scheme, which included slates of fake electors from states falsely claiming he won.

While the new Electoral Count Reform Act approved by Congress has clarified the post-election processes — to more speedily resolve legal challenges and reinforce that the vice president has no ability to change the election outcome on Jan. 6 — the new law is by no means ironclad.

Much depends on the people involved, from the presidential winners and losers to the elected leaders in Congress and the voters across America putting their trust in the democratic system that has stood for more than 200 years. Over the weekend, Trump said he and House Speaker Mike Johnson have a "little secret" for winning the election.

Voters are worried about post-election strife

A poll from The Associated Press-NORC Center for Public Affairs Research found that American voters are approaching the election with deep unease about what could follow.

Dick Gephardt, the former House leader, now serves on the executive board of the nonpartisan Keep our Republic, which has been working to provide civic education about the process in the presidential battleground states of Michigan, Wisconsin and Pennsylvania.

"We are concerned about one thing and one thing only: Can Americans still have valid trust in elections and can we have consistently a peaceful transfer of power in all offices, including the presidency?" Gephardt said in a briefing earlier this month.

"January 6th in 2021 was really a wake-up call, I think, for all of us," he said.

It's not just the onslaught of legal challenges that worries democracy groups, as dozens of cases already have been filed by both Republicans and Democrats even before Election Day. They say the sheer volume of cases has the potential to sow doubt in the election tally and give rise to disinformation, both domestic and foreign, as happened in 2020 when Trump's legal team unfurled far-flung theories that proved to be wildly inaccurate.

As Trump runs to retake the White House, he is already setting the stage for challenges to the election he wants to be "too big to rig." The Republican National Committee has made legal strategy a cornerstone of its Election Integrity program.

Trump is backed by Republicans on Capitol Hill, including House Speaker Mike Johnson, who has adopted similar language, saying he would accept the results only if the election is free and fair.

"We're going to have the peaceful transition of power," said Johnson, who led one of Trump's 2020 legal challenges, on CBS. "I believe President Trump's going to win, and this will be taken care of."

One specific line of attack from House Republicans has been to suggest there will be illegal voting by noncitizens, even though it is a crime to do so, and state and federal reviews have found it to be extremelyrare. Johnson has pointed to past House races, including one in Iowa in 2020 that was won by six votes, to bolster his concerns.

Rep. Joseph Morelle of New York, the top Democrat on the Committee on House Administration, said Johnson is "saying the quiet part out loud," signaling the way Republicans may challenge the outcome.

That "troubles me," he said.

What comes between election and inauguration?

At the Brennan Center, they've conducted war-game-like scenarios for what could happen after the election, at a time when state election officials are facing a resurgence in conspiracy theories and misinformation about voting.

A series of deadlines between Election Day on Nov. 5 and Inauguration Day on Jan. 20 are built into the process, once routine steps that are now important milestones that can be met — or missed.

States are required to certify their electors by Dec. 11 in advance of a meeting of the Electoral College, which is set this year on Dec. 17.

The new Congress convenes Jan. 3 to elect a House speaker and swear in lawmakers. Then, on Jan. 6, Congress holds a joint session to accept the electoral count from the states — a typically ceremonial session presided over by the vice president.

To fortify the process in the wake of the Jan. 6 attack, the Electoral Count Reform Act instituted several changes intended to shore up the process and make sure the disputes are resolved by the time the Congress meets. Legal challenges to the results are to be more quickly resolved, under an expedited timeline for judicial review, all the way to the Supreme Court, if necessary. If a county refuses to certify its results, as some did during the 2022 midterm elections, the governor has more authority to certify the state's tally.

On Jan. 6, the law now requires 20% of the House and Senate to challenge a state's electors to force a vote on rejecting them, rather than a single member threshold from each chamber.

"You know people have a right, if they have a problem with the election, to go to court and be heard," said Rep. Zoe Lofgren, D-Calif. "The thing is, once that's over, it's over."