WASHINGTON — Voters in key states such as Florida and Virginia waited in long lines hours after polls closed Tuesday night to cast ballots, even as politicians and their supporters urged them not to give up despite the long delays.

Candidates turned to social media to encourage voters through the long wait. “#StayInLine #StayInLine #StayInLine” Wisconsin Democratic Senate candidate Tammy Baldwin tweeted. The three states allow voters who were in line when polls closed to cast ballots.

High turnout rather than glitches or problems appeared to be the cause of the long lines, but there were plenty of other problems around the country. Many were in Pennsylvania, including a confrontation involving Republican inspectors over access to some polls and a voting machine that lit up for Republican Mitt Romney even when a voter pressed the button for President Barack Obama.

One Florida elections office mistakenly told voters in robocalls the election was on Wednesday.

The Election Protection coalition of civil rights and voting access groups said they had gotten more than 80,000 complaints and questions on a toll-free voter protection hotline.

“The calls have been hot and heavy all day long,” said Barbara Arnwine, president of the Lawyers Committee for Civil Rights Under Law.

Aside from the lines and scattered other scattered problems with voter access and machine failures, there didn’t appear to be any wholesale disenfranchisement of voters, few tense confrontations among poll monitors and no major instances of election fraud.

“Despite the shameful attempts to suppress voting, voters are standing up,” said Bob Edgar, president and chief executive of Common Cause.

Still, Election Day was far from glitch-free. And voters faced a whole different set of challenges in parts of New York and New Jersey ravaged by Superstorm Sandy.

In Philadelphia, the Republican Party said 75 legally credentialed voting inspectors were blocked from polling places in the heavily Democratic city, prompting the GOP to obtain a court order providing them access. Local prosecutors were also looking into the reports. Democratic Party officials did not immediately return a message seeking comment.

Also in Pennsylvania, Department of State spokesman Ron Ruman said the voting machine in the central part of the state that switched a person’s vote from Obama to Romney has been recalibrated and is back in service. Video of what Ruman called a “momentary glitch” was widely viewed on YouTube.

Pennsylvania was also the scene of what a state Common Cause official called “widespread” confusion over voter ID requirements. The state this year enacted a new photo ID requirement but it was put on hold for Tuesday’s election by a judge amid concern many voters would not be able to comply in time.

Barry Kauffman, executive director of Common Cause in Pennsylvania, said election workers in many places were demanding IDs even though they are not required. It was unclear, however, just how many voters may have been turned away or discouraged.

Also in Philadelphia, a judge ordered a mural of Obama covered up after a Republican election worker snapped a picture of it at a school polling place, according to a statement from the Republican Party.

The battleground state of Ohio was the scene of yet another court battle, this one involving a lawsuit claiming voting software installed by the state could allow manipulation of ballots by people not connected to official election boards. A judge, however, flatly dismissed a lawsuit seeking to stop use of the software.

The Florida robocall glitch occurred in Pinellas County, where the supervisor of elections said about 12,000 voters were wrongly told they could vote on Wednesday.

Spokeswoman Nancy Whitlock said the office had contracted with a company called callfire.com to call voters who had requested mail ballots but had not yet returned them. Whitlock said calls went to those voters without a problem on Thursday, and then again Monday.

Back in Ohio, officials in Franklin County — where the capital city of Columbus is located — barred the tea-party linked True the Vote group from monitoring polling places because applications to do so weren’t filed properly.

Catherine Engelbrecht, president of the Houston-based group, claimed the Ohio Democratic Party was behind pressure that led several local Ohio candidates to withdraw their permission for the group’s members to act as election observers.

Elsewhere, the Election Protection coalition reported problems with ballot scanners in the Ohio cities of Cleveland, Dayton and Toledo; late-opening polling places in minority neighborhoods in Galveston, Texas; and some precincts in the Tampa, Fla., area where voters were redirected to another polling place where they must cast a provisional ballot.

Both political parties in Nebraska accused each other of voter disenfranchisement after a woman claimed she was handed a ballot already filled out for Romney and Republican Rep. Lee Terry — a situation elections officials chalked up to a mistake. The GOP, meanwhile, contended some voters were being falsely told in recorded phone calls that they were ineligible to cast ballots.

In New Orleans, advocates said they received several complaints from large Vietnamese American communities that in at least three major polling places, language services were not being provided to voters needing help with translations. Of particular concern were several proposed constitutional amendments and ballot initiatives, said Jennifer Coco, a volunteer field director with the Louisiana Election Protection Program.

Meanwhile, voters in several storm-ravaged areas in New York and New Jersey expressed relief and even elation at being able to vote at all, considering the devastation from Superstorm Sandy. Lines were long in Point Pleasant, N.J., where residents from the Jersey Shore communities of Point Pleasant Beach and Mantoloking had to cast their ballots due to damage in their hometowns. Many people still have no power eight days after Sandy pummeled the shore.

“Nothing is more important than voting. What is the connection between voting and this?” said Alex Shamis, a resident of hard-hit Staten Island, gesturing to his mud-filled home.

Any voting problems are being closely monitored after months of legal and political battles over more voter ID restrictions and other laws, mostly fruitless hunts for supposedly ineligible people on voting rolls in many states and sustained claims that black and Hispanic voters are being targeted for intimidation and suppression.

Many of these issues could resurface in the courts after Tuesday, particularly if the race between Obama and his Republican challenger, Romney, is too close to call or heads for a recount in states such as Ohio or Florida.

The Justice Department had about 780 observers at key polling places in 23 states to ensure compliance with the 1965 Voting Rights Act and look into any allegations of voter fraud.