WASHINGTON (AP) — President Joe Biden is finding it’s easier to call out attacks on democracy than it is to stop them.

His fundamental rationale for running for president was that America’s democratic traditions were in jeopardy. Now, 20 months into his presidency, the dangers are worse, Biden’s warnings are more dire -- and the limits of his own ability to fix the problem are clearer.

Former President Donald Trump continues to stoke the baseless claim the 2020 election was stolen, and even now advocates for the results in certain battleground states to be decertified even though the falsehood has been rejected by dozens of courts and his own attorney general. The belief has taken deep root in the Republican Party, with dozens of candidates insisting Trump was right.

Never in the country’s history have elections taken place in a climate where one party has so frontally questioned the integrity of the electoral process and actively sought to undermine confidence in it.

“We're in an unprecedented situation here, because Biden's predecessor has shown a flagrant disregard for the Constitution of the United States, and now others are following that path,” said Princeton historian Sean Wilentz, who was among a group invited to the White House recently to put today's challenges in historical context. “It could be dangerous.”

Biden has found, even with the megaphone of the White House, how difficult it is to counter the Trump-inspired narrative and the millions of Americans who believe it. Trump allies have been going around the country peddling lies about the 2020 election and conspiracy theories about voting machines, while Republican candidates running for office this year have repeated his lies to their supporters –- messaging that has reached a broad audience.

Every U.S. president swears to “preserve, protect and defend” the U.S. Constitution, but even in ordinary times there is no playbook for safeguarding it. Biden took that oath as the nation was facing challenges unmatched since perhaps the U.S. Civil War, in the view of some historians.

In a speech earlier this month at Philadelphia’s Independence Hall, Biden described democracy as “under assault” and pledged that it was the work of his presidency to defend it. But he also said the solution had to be bigger than him, that he can’t turn back what he sees as a years-long backslide in American political norms on his own.

“For a long time, we’ve told ourselves that American democracy is guaranteed. But it’s not,” he said. “We have to defend it, protect it, stand up for it - each and every one of us.”

Has Biden himself done enough?

His efforts at persuasion don’t seem to have produced any significant shift in public opinion. His push for voting rights legislation in Congress has for the most part fallen short.

Beyond the president's increasingly drastic warnings, White House officials point to the administration’s efforts to push voting rights safeguards through Congress and to their support for the Electoral Count Act, which would patch ambiguities exploited by Trump and his allies.

The Department of Justice is prosecuting those who violently stormed the Capitol. More than 870 people have been charged and more than 400 convicted.

The administration also has sounded the alarm about domestic extremist groups. There's an increasing overlap with politically-fueled violence, as a growing number of ardent Trump supporters seem ready to strike back against the FBI or others they consider going too far in investigating the former president. And the National Security Council has developed a whole-of-government strategy to counter domestic violent extremism, which U.S. intelligence officials have called the top threat to homeland security.

While voters ranked threats to democracy as the most important issue ahead of the midterm elections, according to an NBC News poll late last month, the conspiracy theories pushed by Trump and his allies have succeeded in sowing doubts about the integrity of U.S. elections in a large swath of the population.

Two-thirds of Republicans believe Biden wasn’t legitimately elected president, according to an AP-NORC poll. They believe that votes were switched, or voting machines were corrupted en masse, or that fake ballots were cast in favor of Biden because pandemic-era policies made voting too easy.

Trump-backed candidates are winning primaries and some will make it to Congress. In the states, nearly 1 in 3 Republican candidates for offices that play a role in overseeing, certifying or defending elections supported overturning the results of the 2020 presidential race.

Candidates have signaled a new willingness to simply refuse to accept the results of their election if they lose. And election workers across the country are getting death threats and are harassed online, pushing many to just resign.

“We are very clearly playing with fire with some of the new tactics, allowing them to proliferate around the country,” said Matthew Weil, the executive director of our Democracy Program at the Bipartisan Policy Center think tank. “It’s: ‘If my candidate loses, I’m going to drag it out as long as possible. I can cut the legs out from the person who beat me from taking office.’ That’s a new feature and it’s pretty dangerous. We can’t have an election system where people aren’t willing to lose.”

Checking the antidemocratic forces within Trumpism is not just a policy aim, it's a political endeavor as well, and that clouds the picture.

Biden aides say his best tool to try to preserve democracy is his use of the bully pulpit to make clear to voters that they play a vital role in participating in the electoral process and deciding whom to put into positions of influence.

He isn’t the only one sounding the alarm. The special congressional committee investigating the 2021 Capitol insurrection has delivered the same message, as have election officials in states across the country, historians and other lawmakers.

Administration allies say Biden’s efforts have resonated with voters, particularly as Trump’s behavior in late 2020 and early 2021 has been cast into stark relief by the Jan. 6 committee.

But the president's remarks have largely been dismissed by Republicans unwilling to break with Trump.

Former Vice President Mike Pence, whom Trump supporters threatened to hang on Jan. 6 and who hid in a secure location beneath the building as the masses hunted him in the halls, decried Biden's comments after the Philadelphia speech.

“Never before in the history of our nation has a president stood before the American people and accused millions of his own countrymen of being a ‘threat to this country,’” Pence said in remarks to conservatives.

Former U.N. ambassador and former South Carolina Gov. Nikki Haley called Biden “the most condescending president of my lifetime.”

The struggle the nation is facing goes beyond political parties, though. And “unless and until enough people fight for, protect and build our democracy, the fever we see today will continue,” said Melody Barnes, head of the University of Virginia Karsh Institute of Democracy.

The closest parallel, historians say, has been the Civil War era, when war broke out after Southern states wouldn’t recognize Abraham Lincoln had been elected president. Following the end of fighting, there was a continued refusal to accept the rule of law during Reconstruction, as deep racism and violence proliferated, resulting eventually in the Jim Crow era.

At critical moments, U.S. leaders have taken a stand to protect the nation from itself. George Washington left office to ensure future leaders would willingly walk away, too. Gerald Ford pardoned Richard Nixon after Watergate -- a wildly unpopular move in 1974 but one that has since been viewed more as an effort to push the country past a national nightmare.

Biden, at a summit this past week on countering hate-fueled violence, talked about how good he felt years ago when he worked successfully with Republicans in the Senate to get the Voting Rights Act extended. “And I thought, well, you know, hate can be defeated,” he said.

“But it only hides,” he said with a sigh. “And when given any oxygen, it comes out from under the rocks.”