(WASHINGTON) — President Donald Trump’s inflammatory comments at the end of Tuesday’s debate have heightened the concern over the potential for intimidation and even violence at the polls on Election Day, experts on domestic extremism and voting rights told ABC News. They’re also a stark reminder for law enforcement to be prepared, and for voters to know their rights, the experts said.

“Some of these groups will be listening to his false claims of fraud, and you put that in combination with his refusal to condemn white supremacists and civil unrest — it really is a very thinly veiled call for his most militant supporters to go to the polls,” said Mary McCord, a longtime national security official and Georgetown University Law professor.

At the debate, the president refused to condemn white supremacy or discourage his supporters from engaging in “civil unrest” as election results come in, instead urging them to “go into the polls and watch” for disproven claims of widespread of election fraud. When asked again Wednesday if he would denounce white supremacy, Trump claimed to reporters, “I’ve always denounced any form of that.”

Still, the president’s comments Tuesday are incendiary ingredients, McCord and another expert told ABC News, that increase worry over the potential for incidents of voter intimidation and violence that were already brewing as millions of Americans go to cast their votes, and have placed new focus on strategies to defuse the tension.

“Based on the presidents words, and the fact that his words generally inspire action by his supporters, every local law enforcement agency should be developing an operation plan on how they will handle voter intimidation on Election Day and how they will deal with acts of violence,” said John Cohen, the former undersecretary for intelligence at the Department of Homeland Security (DHS) under President Barack Obama and an ABC News contributor.

Philadelphia Mayor Jim Keeney announced on Wednesday the city, where Trump has inaccurately suggested voter fraud is occurring, is doing just that.

“We’re working on a plan now to make sure the polls are safe and secure,” he said.

A group of 11 Democratic governors on Wednesday also released a joint statement reaffirming their commitment to safety, and condemned acts of suppression and those who incite it, without directly naming Trump.

“The name of the game for the 2020 election is going to be preparedness,” said Myrna Perez, who is the director of the Brennan Center’s Voting Rights and Elections Program. “There are state and federal laws that protect voters from intimidation and violence at the polls, and election administrators are doing a lot of thinking about how to prevent things from getting out of hand.”

A widespread education campaign that ensures enforcement and trained poll workers what to do if a situation escalates will be critical, she said.

Concern regarding the potential for voter intimidation began to simmer before Tuesday’s debate. Last month in Northern Virginia, videos emerged of a group of Trump’s supporters gathered at a polling location in the Washington, D.C., suburb of Fairfax, and an election official there said the disturbance caused voters to feel intimidated, according to the New York Times.

Virginia’s Democratic attorney general, Mark Herring, said his team was exploring how to better protect voting places moving forward “given the possibility that this behavior could occur again.”

Jessica Bowman, the Deputy Commissioner of the Virginia Department of elections, said, “We will work with state and local partners to make sure voters can cast their votes safely and securely.”

The Republican Party of Virginia appeared to brush off the incident, tweeting, “Quick! Someone call the waaaambulance.” And nationally, Republicans have disavowed the notion that Trump supporters would do anything to try and block polling places or intimidate voters.

“The RNC and Trump Campaign will have a robust and aggressive Election Day Operations and litigation plan in place and will spend millions to ensure the election is run fairly and honestly,” a spokesperson for the Republican National Committee said previously. “Specifically, our efforts will ensure that no legally eligible voters are disenfranchised, that all votes are accurately and legally tabulated, and that voters are not confused about laws and procedures.”

Informing voters of what to watch for on Election Day and making sure they are aware of their rights without deterring them from showing up at the polls is a tough balance to strike, Perez said.

“Intimidation and violence at the polls is a form of voter suppression,” she said, “but we do not want to needlessly scare voters that they are going to run into trouble, but we are expecting bumps.”

In August, an internal Department of Homeland Security bulletin warned that “white supremacist extremists” posed the most significant “lethal” threat to the election this year.

“We continue to assess lone offender white supremacist extremists and other lone offender domestic terrorist actors with personalized ideologies, including those based on grievances against a target’s perceived or actual political affiliation, policies, or worldview, pose the greatest threat of lethal violence,” said the bulletin, which was first obtained by The Nation and later confirmed by ABC News.

No specific credible threats had yet been identified, the bulletin added.

Concerns about what extremist groups may do on Election Day also come against a backdrop of sporadic violence across the country this summer between far-right groups and counter-protestors. In August, a 17-year-old who was allegedly part of a militia group was arrested in the shooting deaths of two protestors in Kenosha, Wisconsin. Later that month, armed militias and far-right activists faced off against Black Lives Matter protesters in a violent clash in Portland, Oregon, according to reports. In July, three members of an armed militia were shot by another militia in Louisville, Kentucky at a protest calling for justice for Breonna Taylor.

As pockets of unrest have continued to crop up, Trump and members of his family and campaign team have been actively pushing claims — which have been widely refuted — that they expect to see widespread election fraud in November. At the close of Tuesday’s debates, Trump coupled those claims by urging his supporters to “to go into the polls and watch very carefully” for fraud, despite a lack of evidence that widespread election fraud exists.

McCord said that brand of propaganda could motivate extremist groups to engage in or incite Election Day confrontations.

“That is a dog whistle for these groups to think, ‘We better deploy to protect the vote,’” McCord told ABC News.

Trump’s embrace of poll watchers has also been pushed online by his campaign, which is attempting to recruit what it calls a Trump “army” to monitor polling stations around the country on Election Day. A video on a campaign website explaining the recruitment effort specifically stokes fears about election fraud and calls on voters to get to the polls to stop it, claiming that the effort is attempting to make sure that anyone who is “legally entitled to vote, has the opportunity to vote, once.”

“We all know that the democrats will be up to their old dirty tricks on Election Day to make sure that President Trump doesn’t win,” the video warns. “That is why our goal is to cover every polling place in the country with people like you.”

Poll watchers are legal but controversial workers used by both parties during election season to observe the voting process, relay information back to their parties, and watch for fraud. In some states, watchers are permitted to challenge a person’s eligibility to vote, but they are also not supposed to interfere with voting aside from reporting issues through to official channels.

Each state has its own set of laws and qualifications that guide poll watcher activity. In many states, poll watchers are only allowed on Election Day and are not permitted to travel across state lines or into other counties to watch. States also set limits on the number of poll watchers allowed at polling locations or in precincts.

The use of campaign poll watchers has a troubling history in the U.S. The 2020 election is the first presidential election since the expiration of a decades-old consent decree that had long prevented the Republican National Committee from engaging in at-the-ballot security measures.

The RNC had entered into the agreement in 1981 after Democrats accused them of engaging in various poll watching measures in New Jersey that they said amounted to voter suppression, which included the deployment of armed off duty officers to polling sites in minority communities. The decree did not extend to the Democratic National Committee. Now, after a judge declined to extend the decree in 2018, that restriction is no longer in place. The RNC will still have to follow state laws, however.

RNC Chairwomen Ronna McDaniel defended her party’s efforts against claims that its operation will be used to target minority voters.

“Our access is about more people voting, not fewer,” McDaniel wrote in an op-ed in the Washington Post last month. “That’s the opposite of Democrats’ claims of ‘voter suppression’ […] Now that the playing field is level again, the RNC is investing heavily to ensure that all our volunteers and poll watchers are trained and abide by each state’s laws for observing the voting process.”

An effort to recruit 50,000 poll watchers is this season is already under way, Justin Clarke, one of the Trump campaign’s top lawyers, said earlier this year while praising the end to the consent decree.

“For about 40 years the Republican Party has been fighting this battle with one hand tied behind its back,” Clarke said while speaking on a panel about voter fraud at the Conservative Political Action Committee (CPAC) in March. “In 2020, we have a brand new opportunity to be able to activate an Election Day operations program that’s really robust.”

That effort by Republicans has created “extra cause for worry” that voter intimidation could occur, according to Perez, the Brennan Center expert.

“What we’ve seen about fraud have been highly racialized,” Perez added. “If the wrong people hear it, it could lead to intimidation and voter suppression by individuals, by private actors who don’t realize how incorrect and untruthful some of these lies are.”

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