Richard Wolf and Kevin McCoy

USA TODAY

Tens of millions of Americans who descended on the polls Tuesday faced hours-long lines, sporadic equipment failures and confusion about polling places — but little of the violence or vigilantism that had been feared.

Problems cropped up in Arizona, Florida, North Carolina, Ohio, Pennsylvania, Virginia and other key battleground states that would decide whether Hillary Clinton or Donald Trump wins the presidency. Most involved election administration issues that have plagued the polls for decades, however, rather than incidents of voter fraud or intimidation fueled by Trump's warning of a "rigged" election.

A coalition of more than 100 civil rights and voting rights groups running a national election protection hotline reported that 40% of its calls came from African American and Hispanic communities, a possible indication that minority voters were being targeted. The majority of complaints came from California, New York, Texas, Florida, Pennsylvania and North Carolina, with Florida seeing particularly high levels of voter misinformation.

“There is tremendous disruption at the polls today," said Wade Henderson, president of the Leadership Conference on Civil and Human Rights. "This election may be the most chaotic election … in the last 50 years.”

The most widespread problems appeared to occur in North Carolina and Colorado, two crucial swing states:

In Durham, N.C., electronic poll books that are used to check voter registration were down in the morning, forcing voters to wait longer and use paper back-up copies. The Southern Coalition for Social Justice filed a lawsuit in hopes of forcing the Durham County Board of Elections to keep polls open an additional 90 minutes. In the end, voting was extended by the state Board of Elections for up to an hour in eight precincts affected by the malfunctions.

Judith Browne Dianis, co-director of the Advancement Project, a civil rights group, said the Durham problem "makes for the perfect storm of a contested election" following a dispute over legislative voting restrictions struck down in federal court. "It’s going to be the battleground of the battleground," she said.

In Colorado, portions of the state’s voter-verification system went down for about 30 minutes in the afternoon, briefly forcing state officials to issue provisional ballots to an undisclosed number of voters, and also briefly preventing them from processing mail ballots. The cause of the problem was under investigation. Colorado Democrats went to court in a bid to keep the state's polls open until 9 p.m., but a Denver judge denied the request.

While violence generally was limited to pushing and shoving at a few polling places, a fatal California shooting near a polling location in Azusa, part of Los Angeles County, left several more people injured, scattered voters and forced a lockdown. Officials diverted voters to other polling places where they could use provisional ballots.The incident did not appear to have any connection to the election, the Los Angeles County Sheriff's Department said in a statement.

Francisco Vargas, 20, had just started to fill out his first presidential ballot. “I was actually voting when we heard the gunshots,” he said. At least 40 people were trapped inside, along with a dozen preschoolers getting a tour of the facility. “It was just a really, really intense first-time voting — a fitting end to a crazy presidential election.”

While racial and ethnic minorities had felt threatened by Trump's calls for self-styled poll watchers, few examples of blatant discrimination were reported. In Ohio, the eligibility of some black voters was challenged at the polls, according to voting rights groups. Voters in a heavily Somalian-born community who had conflicting addresses were told to use provisional ballots when none were available; signs posted in black neighborhoods warned that voter fraud is a crime.

And in one of the few glitches with political overtones, a problem with the calibration of electronic voting machines in Lebanon County, Pa., caused about a half dozen machines to display what voters thought were straight Republican tickets as straight Democratic tickets. Poll workers alerted the county elections bureau, and voters were able to change their ballots, said Michael Anderson, director of the Lebanon County Bureau of Elections.

Disputes and lawsuits

Nearly 90 million Americans were expected to vote Tuesday, in addition to more than 46 million who voted early or by absentee ballot. Voters were being watched by thousands of federal monitors, voting rights advocates, conservative watchdogs and even international observers looking for anything from dirty tricks to acts of violence.

Early voters not swayed by late campaign events

Liberal and conservative interest groups were being extra vigilant because the presidential race tightened in recent days, and because Trump urged supporters to watch polling stations in "certain areas" for signs of fraud. Much of the back-and-forth involved liberal groups seeking to ensure that voters were given the right to cast ballots, and conservatives trying to limit access.

The Trump campaign went to court in Nevada on Tuesday, complaining that the Clark County Registrar kept an early voting site at a Latino market open two hours past closing time last Friday night. State law allows voters in line when polls close to cast ballots; Trump's lawsuit claims additional voters were allowed to join the line. The complaint, which could ultimately invalidate the votes in question, was swiftly denied.

“To approve an extraordinary writ like this is going to require an extraordinary reason,” said David Becker, executive director of the Center for Election Innovation and Research and a former Justice Department voting rights lawyer. “Trump’s lawyers didn’t show that.”

Problems were anticipated throughout the day, particularly in Southern states freed under a 2013 Supreme Court ruling from needing federal clearance for changes in voting procedures. Fourteen states with new election laws, from Arizona to New Hampshire, also were expected to encounter difficulties.

Karen Hobert Flynn, president of Common Cause, said last-minute polling place changes and other problems in Arizona were "causing real confusion for many voters."

Justice Dept. cuts number of staff it sends to enforce voting rights

“This is an election cycle that’s just been marked by evidence of the resurgence of voting discrimination,’’ said Kristen Clarke, president of the Lawyers’ Committee for Civil Rights Under Law, which oversees the election protection effort. “This is a moment when we’re seeing first-hand the impact of the Supreme Court’s ruling which gutted the Voting Rights Act.’’

Observers came from as far as Europe and South America to see whether America's democratic system could withstand pressures from within the political system and beyond — extending, perhaps, to efforts by Russia and others to hack into election information systems.

Voting machines fail

The most persistent problems were those that crop up every election cycle, such as closed or relocated polling stations, confusion over new voting requirements, and faulty voting machines. Those and other problems led to long lines in North Carolina and Texas during the popular early voting that preceded Tuesday's balloting.

By mid-afternoon Tuesday, problems being reported included long lines and delayed poll openings in New York; malfunctioning voting machines in Virginia; and confusion with closed or delayed-opening polling places in Georgia and Texas. Among the specific incidents:

In Dover, N.H., misinformation that polls would close at 8 p.m. led officials to extend voting an hour from the pre-planned closing time of 7 p.m. The city is a Democratic stronghold in a crucial battleground state.

In Maricopa County, Ariz., Democratic officials asked a judge to keep polls open for two more hours following problems with voting machines and provisional ballots that caused long lines. The request, like that in Colorado, was denied.

In Washington County, Utah, election officials had to scramble to get electronic voting machines back up and running after machines at many precincts failed to operate immediately after polls opened at 7 a.m. Only 99 of 380 machines had memory cards programmed correctly. Voters were given paper ballots instead.

In Philadelphia, would-be voter Chris Calvert tweeted that both voting machines were broken at his polling place. “No one can vote in our district today. Hundreds of angry voters,” he wrote. Federal law requires election officials to give voters provisional paper ballots in such cases.

In a Detroit precinct in the battleground state of Michigan, the machine that counts ballots was not working from the very beginning of the morning, causing confusion and anger among voters. Workers at the precinct told voters they could either leave their ballots in a secure box to be counted later or wait for a technician.

In Virginia, two convicted felons who said their voting rights were restored years ago reported trouble casting ballots. Fariyd Muhammad, 73, needed four trips to his Richmond polling place; he and Antonio Hargrove, 55, of Alberta, about 60 miles south of Richmond, were given provisional ballots. “I think it was unfair,” Hargrove said.

Broken ballot-scanning machines and other problems slowed voting at some polling places amid heavy turnout in New York City. Only one of two scanners was functioning at a polling place in Manhattan’s Gramercy Park neighborhood Tuesday morning, leading to a line of hundreds of people by 8:30 a.m. The same thing happened at Public School 154 in Manhattan’s Harlem neighborhood, where Megan Arend tweeted the situation was causing "complete chaos and discouraging voters.”

Court battles

Until Tuesday, most of the battles had been fought in federal courtrooms rather than the streets. The Supreme Court weighed in Monday, denying efforts by Democrats to bar Trump's supporters from polling places in Ohio over the chance they would intimidate voters. Conservatives previously won an Arizona legal battle over how ballots are collected, while liberals prevailed in voting rights lawsuits in North Carolina and Wisconsin.

The Justice Department dispatched more than 500 monitors to 28 states, a reduction from nearly 800 in 2012 that reduced the government's presence inside polling places. Their task: to determine whether voters were subjected to racial discrimination or other barriers related to language differences or disabilities.

Feds sending poll monitors to Detroit, Dearborn Heights, Hamtramck

Federal authorities have said the decentralized and antiquated nature of the country’s vote tabulation systems would be difficult to hack, and on Tuesday they said no serious issues had been reported. But the Department of Homeland Security, FBI and other agencies were focused on potential Internet outages or terrorist plots timed to the election that might be designed to sow fear.

The election protection coalition of civil right and voting rights groups claimed to have more than 4,500 volunteers fielding calls to 866-OUR-VOTE at its command center in Washington, D.C., and regional centers across the country. It also had poll monitors in 28 states.

Election officials fear untrained poll watchers

And in an unprecedented effort to monitor the voting process, more than 1,000 reporters, editors and students collaborated to spot and verify reports of long lines, voter intimidation and other polling place problems.

The USA TODAY Network is part of that effort, along with ProPublica, Google News Lab, Univision Noticias, the City University of New York Graduate School of Journalism, First Draft, and WNYC Radio. The information is being published on the Electionland website and used in separate stories.

Early Tuesday, Electionland reported that Urban Outfitters, a popular retailer with conservative ownership, tweeted incorrectly to its 1 million Twitter followers that voters must bring voting registration cards to their polling places. The company said it would correct the voter guide immediately.

Several other issues Tuesday focused on Trump and his family:

In New York, police arrested two women who staged a topless protest at the Republican nominee's voting precinct. Tiffany Jordan Robson, 28, of Seattle, Wash., and Neda Topaloski, 30, of Montreal, Canada, were issued summonses for electioneering within 100 feet of a polling place.

Eric Trump tweeted a ballot selfie showing he had voted for his father for president. He deleted the tweet after Electionland flagged it and tweeted that polling place photos are illegal in New York.

Donald Trump Jr. avoided a similar problem by tweeting a photo of himself and his family outside their polling place.

Contributing: Deborah Berry and Kevin Johnson in Washington, D.C.; Elizabeth Weise in San Francisco; Trevor Hughes in Denver; Melanie Eversley in McLean, Va.; Daniel Walmer, Lebanon (Pa.) Daily News; David DeMille, The Spectrum, Cedar City, Utah; Barrett Newkirk, Christopher Weddle and Daniela Franco, The Desert Sun of Palm Springs Calif.; Lauren Gustus, Fort Collins Coloradoan; Detroit Free Press; ProPublica.

More election coverage from USA TODAY:

• How to make sense of what's happening as polls close

• Plot Trump's or Clinton's path to 270 electoral votes

• See the latest national and state presidential polling averages

• Check out poll closing times in each state

• Candidate info and ratings for all races