From now through Election Day and beyond, NBC News is tracking reports of voting problems and irregularities. That includes claims of fraud or intimidation, long wait times, machine snafus, controversies over counting votes and anything else that could threaten the right to vote or the integrity of the process.
We will update this list frequently, with the newest developments at the top. Scroll to the bottom for more information on this project.
10/31 1:53 p.m.: Dems sue Trump campaign over alleged voter intimidation in four states
Democrats are suing the Trump campaign, Trump ally Roger Stone, and four state Republican parties, alleging illegal voter intimidation.
More from NBC News:
Analysis: The vengeful world of Donald Trump, and why it matters
First read's morning clips: The latest in the Comey surprise
Eric Holder condemns FBI Director Comey over Clinton 'mistake'
The four lawsuits, filed Monday, charge that state parties in Arizona, Nevada, Ohio and Pennsylvania are teaming up with the Trump campaign and Stone to raise unfounded fears about voter fraud and intimidate minority voters. The lawsuits cite the Voting Rights Act and the Ku Klux Klan Act, which aim to prevent voter intimidation.
"The campaign of Donald J. Trump, Trump's close advisor Roger J. Stone, Jr., Stone's organization Stop the Steal Inc., the Nevada Republican Party ("NRP"), and others are conspiring to threaten, intimidate, and thereby prevent minority voters in urban neighborhoods from voting in the 2016 election," the Nevada complaint alleges.
The suits ask the judges to bar activities that could lead to voter intimidation.
Trump has numerous times talked about the threat of voter fraud, and has urged his supporters to closely monitor voting in "certain areas"—widely understood as a reference to minority neighborhoods. He has sometimes singled out Pennsylvania as a likely location for fraud.
The Trump campaign did not immediately respond to a request for comment. An email sent to an address provided on the website for Stone's Stop the Steal was not immediately returned.
Trump has offered no evidence that such fraud is occurring, and experts say voter impersonation fraud is extremely rare.
Stone, a controversial Trump supporter and one-time adviser, is reportedly organizing a volunteer "exit polling" operation that would take place in minority areas across the country.
Marc Elias, the lead lawyer on the lawsuits, is a top lawyer for the Hillary Clinton campaign.
Rick Hasen, a leading election law scholar, wrote Monday: "It is not clear that a court would issue a vague order to stop 'voter intimidation,' as requested in the relief in these suits (as that term would be vague and difficult to enforce). But the suits will first bring publicity to the activities, and second get these parties on record stating that they do not plan on engaging in voter intimidation, which itself could be useful in the event of problems on election day.
10/31 11:32 a.m.: North Carolina sued over alleged illegal purge of thousands of voters
Voting rights lawyers have filed suit against North Carolina and three counties on behalf of the state's NAACP chapter over what they allege is an illegal purge of the voter rolls.
The complaint charges that the counties have been "cancelling the voter registrations of thousands of North Carolina voters who have been targeted in coordinated, en masse challenge proceedings brought in the final weeks and months before Election Day, and whose right to vote has been challenged solely on the basis of a single piece of undeliverable mail, in clear violation of the National Voter Registration Act ("NVRA") and other federal laws."
A spokesman for the North Carolina Board of Elections didn't immediately respond to a request for comment on the lawsuit, but the boards said last week that it believes the removals of voters are legal.
The three counties named are Cumberland, Moore and Beauchamp.
The NC NAACP laid out the background behind the case last week. (See entry at 10/27 2:40 p.m.)
Update 1:55 p.m.:
Kim Westbrook Strach, executive director of the North Carolina State Board of Elections, responded in a statement:
"These voter challenges were filed by private citizens, not elections officials. Our independent agency administers state and federal election laws. The statutes at issue are decades old and are common across the country and widely regarded as compatible with the National Voter Registration Act (NVRA). If the plaintiffs are right, then most states are wrong."
10/31 11:27 a.m.: Texas county ordered to stop saying photo ID needed to vote
A Texas judge has ordered local election officials in San Antonio to stop incorrectly telling voters that photo ID is required to cast a ballot.
The Friday afternoon order by Judge Michael Mery came after voting rights advocates sued Bexar County, alleging that signs at polling places and other materials put out by the county say photo ID is required.
Jacquelyn Callanen, the elections director for Bexar County, has said she will comply with the order.
Texas's voter ID law was recently softened by a federal court. Voters without acceptable photo ID can nonetheless vote if they sign an affidavit affirming their identity.
Numerous reports suggest Bexar County is far from the only Texas county continuing to incorrectly tell voters that photo ID is required.
10/28 2 p.m.: Judge wants Florida to add voters to rolls
A federal judge wants to make sure Florida adds thousands of new voters to the rolls in time for the election.
At a hearing Friday morning, U.S. Judge Mark Walker questioned Maria Matthews, the director of the elections division in the Florida secretary of state's office, about would-be voters who registered during the seven-day extension of voter registration, but have yet to be added to the rolls.
A spokeswoman for Secretary of State Ken Detzner said in a statement issued hours later that more than 21,000 applications remain pending, while more than 106,000 have been processed since October 11. For nearly 15,000 of those that are still pending, the state says the voter provided incomplete or unverifiable information.
Citing the chaos caused by Hurricane Matthew, Walker earlier this month ordered Florida to extend the voter registration period for seven days beyond the original October 11 deadline. Gov. Rick Scott had initially refused.
Pamela Goodman, the president of the Florida chapter of the League of Women Voters, which originally brought suit to extend the deadline, said that she expected that by Monday, the number of complete but unprocessed applications should come "dramatically down."
"We are pleased that the judge is watch-dogging this as closely as he is, " said Goodman. "I think it's good that Secretary of State understands that all eyes are on Florida, and all eyes are on his office."
Detzner, a Republican, has in the past supported restrictive voting rules, including a flawed purge of the rolls ahead of the 2012 election.
10/28 12:11 p.m.: Miami-Dade County election worker arrested for suspected voter fraud
Gladys Coego, a temporary election worker in Miami-Dade County, was arrested Friday after being caught illegally marking ballots, the Miami Herald reported.
Coego, 74, is expected to be charged with two felony counts of illegally marking another person's ballot. Her job required her to open mail-in ballots.
The illegal votes were cast in favor of Miami mayoral candidate Raquel Regalado, a Republican. It's not known how many illegal votes were cast.
Investigators have said Coego hid a black ink pen in her purse, then used it to mark ballots in which the mayoral race had been left blank. They said Coego admitted to what she had done after being caught by a co-worker, but didn't say why.
10/27, 5:36 p.m.: N.C. NAACP wants more help for voters affected by Hurricane Matthew
The North Carolina NAACP says the state isn't doing enough to accommodate voters still recovering from Hurricane Matthew.
Rev. William Barber II, the group's president, said the NAACP has asked North Carolina to add evening and weekend voting hours, and to set up mobile voting units for voters in certain eastern counties that were affected by the storm earlier this month.
Patrick Gannon, a spokesman for the state board, told NBC in a statement that the state extended the voter registration deadline by several days in affected counties as a result of the hurricane. "Also, the State Board is mailing postcards to all absentee voters in the affected counties who have not yet returned their ballots in case they were lost or not delivered because of the storm," Gannon added. "The postcard reminds voters of their voting options."
Gannon said the state is prepared to take further action if it deems it necessary.
The controversy comes after several county election boards, which are controlled by Republicans, reduced early voting sites and locations compared to 2012, acting after the state GOP urged them to do so in order to benefit the party's candidates. In Guildford County, which cut early voting sites for the first week of early voting from 16 in 2012 to just one this year, some voters reported waiting three hours to vote last week, and after two days, voting rates were dramatically down from 2012.
10/27, 2:40 p.m.: Advocates say North Carolina voters are being illegally removed from rolls
Civil rights advocates in North Carolina say voters have been illegally removed from the rolls after their eligibility was challenged. The state has said the thousands of removals are legal.
Around 4,500 voters in Beaufort, Moore and Cumberland counties were challenged, in many cases after mail sent to their address was returned, the state confirmed in a letter sent Thursday to the NAACP. The majority were in Cumberland County, the letter said. North Carolina law allows for private citizens to formally challenge a voter's eligibility ahead of an election.
Cumberland County elections director Terri Robertson told NBC News that around 5,000 voters had been challenged since the start of the year, and around 3,000 had been removed. She said she was too busy with the election to provide exact numbers.
Beaufort County elections director Kelli Hopkins told NBC News that 14 voters have been removed, and hearings are pending for about 90 more.
Moore County elections director Glenda Clendenin told NBC News that between 300 and 400 voters had been removed in the most recent of two rounds of removals. She declined to estimate how many had been removed in the first round.
All three officials said that if challenged voters don't respond to letters or show up to a hearing on their eligibility, they are typically removed.
Voting rights lawyer Penda Hair said on a Thursday conference call organized by the NAACP that the group believes over 300 Cumberland County voters have been removed.
One challenged voter, Grace Hardison of Beaufort County, is a 100-year-old African-American woman who for much of her life couldn't vote thanks to Jim Crow laws, and has been on the rolls for 30 years, her nephew Greg Satterthwaite said on the NAACP call. The challenge to Hardison was eventually withdrawn and she remains on the rolls.
Hair said the removals violate the federal Motor Voter law, which bars systematic purges of the rolls 90 days ahead of an election. Last week, the NAACP notified the state board of elections in a letter that intends to sue.
In a response sent Thursday to NAACP North Carolina president William Barber II, state board of elections director Kim Strach maintained that the removals were legal because they're being done on an individual basis rather than systematically.
10/27, 11:11 a.m.: Trump tweets about "vote flipping" in Texas, but election officials can't verify
Donald Trump tweeted Thursday morning:
NBC News spoke with Toni Pippins-Poole, the elections director for Dallas County, where some of the reports of vote flipping have occurred. She explained that the county's protocol for when voters complain about problems with machines is to cancel the ballot and recalibrate the machine. If they get a second complaint about the same machine, they take it out of service. She said five machines have so far been taken out of service.
However, Pippins-Poole said that in no case have administrators been able to replicate the error reported by a voter, and every voter who complained has ultimately been able to vote successfully.
Pippins-Poole said a lot of the complaints they've received stem from the fact that the "Summary Page" that voters see at the end says "Incomplete" if they didn't vote in every race. This often confuses voters into thinking that the votes they did cast have not been recorded (though it wouldn't explain flipping votes from one candidate to another). She said there can also be other forms of voter error, such as when jewelry touches the screen, accidentally registering a vote.
In terms of any kind of conspiracy to benefit one candidate and hurt the other, as some on social media are suggesting, Pippins-Poole said: "That is not happening."
Other election directors where voters have complained about flipped votes have also attributed the problem to voter error.
However, many touch screen machines are over a decade old, so election experts have expressed concern about the potential for malfunctions. A machine in Pennsylvania in 2012 changed votes from Obama to Romney, and there have been credible reports of votes being changed from Clinton to Trump in North Carolina this year.
10/26, 12:34 p.m.: Reports of Texas voter ID law being incorrectly enforced
Poll-workers and flyers in some Texas counties have incorrectly told voters they need a photo ID to cast a ballot, voting rights advocates say.
The claims add to concerns that Texas is failing to fully implement a federal court ruling that substantially loosened the state's ID law.
The Texas Civil Rights Project has been compiling reports of irregularities in early voting in the Lone Star State, which began Monday. According to the group:
At least two counties, Bexar and Denton, posted outdated flyers which inaccurately tell voters that photo ID is required.
A voter in Denton County reported being turned away for lack of a photo ID.
At at least two sites in Houston, voters said poll workers incorrectly told them they needed ID.
In Denton County, an armed patrol person was seen talking to voters waiting in line.
Alicia Pierce, a spokeswoman for Texas Secretary of State Carlos Cascos, said that in response to the complaints, her office had sent a reminder to counties to use updated flyers, which correctly inform voters that they can vote without photo ID if they sign an affidavit swearing to their identity.
"Clearly it's mistakes when this has happened," said Pierce. "No one's doing this intentionally."
But the reports follow weeks in which Texas has appeared to drag its feet in implementing the federal court ruling. Last month the court found that the state used misleading language in describing the new rules and ordered the state to change it. And it found an earlier public education campaign about the ID law to be "woefully inadequate."
What is this project?
Voting never goes perfectly smoothly in any election. But this year could bring a perfect storm of problems. One presidential candidate has made sweeping claims about the threat of voter fraud, and urged supporters to monitor the polls, raising fears of intimidation.
Restrictive voting laws will be in place in several states, and even recent court-ordered changes to some laws are likely to cause confusion. Most states are using voting machines that are over a decade old and at risk of malfunctioning. And as if that weren't enough, this will be the first presidential election in over half a century without the full protections of the Voting Rights Act.
That's why from now through Election Day and beyond, we'll use this page to track reports of voting problems and irregularities. That includes claims of fraud or intimidation, long wait times, machine snafus, controversies over counting votes and anything else that could threaten the right to vote or the integrity of the process.
NBC News will update this list frequently, with the newest developments at the top.