Political enthusiasts and scores of protestors alike descended on Hofstra University with only hours to go Monday before the first presidential debate between Democrat Hillary Clinton and Republican Donald Trump.

A festival-like atmosphere surrounded the school hours before the highly anticipated show down — students gathered for outdoor campus viewing parties on giant screens, protestors marched through the campus yelling “No Justice! No Peace!” and students ran up to notable figures walking through the campus hoping to capture a snapshot on their phone.

The highly anticipated 9 p.m. political showdown at Hofstra University in Hempstead is expected to draw a record 100 million television viewers, with political analysts predicting 90 minutes of fiery exchanges between two of the most well-known presidential candidates in modern U.S. history.

Monday evening, nearly 100 students stood in line outside a campus student center hoping to get into the debate hall with an undisclosed number of unused tickets given back to Hofstra University by the individual campaigns.

Many of the students received an email a few hours ago telling them to show up in business attire with identification and their voter registration.

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“I’ll stand here for six hours if it means I’ll get into the debate,” said Nevin Shah, 20, a Hofstra junior from Ronkonkoma. “Getting in would be an experience I would tell my children and grandchildren 30 and 40 years from now.”

Several students said Monday they are supporting Libertarian Gary Johnson over the major party candidates.

Johnson, a former governor of New Mexico, did not poll well enough to qualify to take the debate stage with Trump and Clinton. A feud erupted last week on Hofstra’s Facebook page when Johnson backers protested his omission.

Kris Buckley, 18, of Philadelphia, called the third-party nominee a personal hero. “He stands for the socially liberal base but with a fiscally conservative view,” said Buckley, a freshman international business and marketing major who will be voting for the first time.

Kenneth Mulvena, 20, of Bellerose, who wore a face with an image of Johnson’s face and carried a Johnson campaign sign, said his candidate “actually believes in the Constitution.”

The junior political science major added that he appreciates the nominee’s economic stances. “I want a candidate who doesn’t believe in crony capitalism, believes in true free market.”

John Jay LaValle, chairman of the Suffolk County Republican Committee and an early Trump supporter, said he spoke earlier Monday with candidate and called Trump “very relaxed” and “very positive” about the debate.

“He’s really hitting his stride. He’s talking about the issues that are most important to Americans,” LaValle told Newsday of national security concerns.

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LaValle cited a polling lead for the Republican over Clinton among independent voters.

“They just want better government. They are overwhelmingly moving to Mr. Trump,” he said.

Earlier Monday, crowds of students walked the grounds of Hofstra, some carrying political signs.

There was a bit of a carnival vibe, with students jumping inside a bouncy castle shaped like the White House, and at times cheerleaders and a student band roaming the parking lots near the student center.

The broadcast news channels set up on campus and many students gathered near the television cameras, amused by the live coverage and interviews with political personalities.

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As the afternoon hours passed, the crowd swelled into the hundreds, with students carrying signs that expressed ideas on everything from student loan debt to gun violence to abortion.

Hofstra senior Christopher Nieves, 21, carried a sign that read “The tuition is too damn high” in the hope the candidates would talk a little about high student loan debt across the country.

“The banks make a ton of money off of us and my generation has been cast aside,” said Nieves, of Rahway, New Jersey.

Nieves, who said he will graduate with about $120,000 in student debt, switched his major from political science to information technology because he was worried about his job prospects, he said.

Neither Clinton nor Trump is doing enough to address this “crisis” in higher education, he said.

“I’ll vote,” Nieves said. “Probably not for either of them, but we’ll see what they say tonight.”

Regina Volpe, 19, had waited with two friends to enter the giant inflatable castle. She wore a pin that read, “Fight for Your Right to (Political) Party.”

“Amazing to say we are a part of history,” said Volpe, an English major from Scranton, Pennsylvania. The three sophomores removed their shoes and spent about five minutes jumping up and down. It was a nice way to release energy from a jam-packed morning discussing serious issues.

The group spent a good amount of time moving from table to table collecting free T-shirts, mugs, temporary tattoos, pins and tote bags.

“I feel like a kid again,” said Amelia Beckerman, 19, of Princeton, New Jersey. “I’ve been up since 3 a.m. And I definitely think our fist-pumping made it into the CNN live shot.”

The students’ political views seemed to run the gamut, with several of them saying they care more about issues than the candidates themselves.

A crowd of more than 30 students dressed mostly in black formed a circle and observed a moment of silence to call attention to the Black Lives Matter movement, calling for an end to the violent deaths of black men at the hands of police.

Kadeem Adrian, 19, a sophomore, had written on his shirt “When will it stop?”

“We do have a voice, and want to be heard and to be seen,” Adrian said.

Matthew Izzo, on the other hand, was among a few Donald Trump supporters amid a crowd of students holding Hillary Clinton and Jill Stein signs near the MSNBC stage. His sign said: “Hillary Clinton can’t parallel park,” which he said was a facetious way of saying she can’t be trusted.

Izzo, 21, a senior, said he would like to see Trump deliver “a game plan” for conservative principles and his call for a wall to improve security along the southern border of the United States.

“I think he has to bring more substance” now that he’s closer to Election Day, he said. “It’s refreshing to see someone” like Trump, not fearing political correctness, he said, because “he’s not worried about what he says.”

Jada Carter, 18, a freshman, held a pink sign that said “I’m With Her” to signal her support for Clinton, but she said it was difficult to be motivated by her choices. “It’s scary to have to pick out of these two for my first presidential election,” she said.

But in the end “I feel like she’s the better fit. She has way more experience and she’s not a racist” who stereotypes groups of people, Carter added.

Carter hopes the debate will not devolve into “a lot of arguing” so that voters could see a clear choice. She planned to watch with fellow students in her dorm.

Also near the MSNBC’s stage was Meaghan D’Amico, 23, a Hostra graduate student, who was carrying on her shoulders Ariel McHone, 18, a freshman who wanted to be seen on cable news with her Clinton/Kaine sign.

D’Amico said she has not decided whom to vote for, and she will be paying attention to key issues.

“I’m very interested in hearing them lay out their policies” on issues including “women’s health, abortion, LGBT rights and the economy,” she said.

McHone said she supports Clinton because “we should have a female president,” but also because she doesn’t like the other major party candidate.

“I support Hillary because I don’t support Donald Trump,” she said. “We should have a female president for at least once in our lives.”

Libby Creek, 19, a television and film major who was working as a student volunteer, said debate day is a long one but it holds so much opportunity for her. She was assigned to work with Fox News and would be watching the event from the network’s trailer.

“My parents have been texting me every day. They are so excited,” said Creek, of Brookfield, Massachusetts. “They are even hosting their own watch party with friends and family.”

She said she will volunteer until about 2 a.m. and try to get some sleep before her 9 a.m. class on Tuesday.

“Somehow I’ll get there,” Creek said.

Earlier in the day, Stein, the Green Party presidential nominee, was seen speaking to reporters on campus. Low poll numbers will keep her and Libertarian Gary Johnson off the formal debate stage.

Later, the Rev. Jesse Jackson was surrounded by students eager to take their picture with the civil rights leader outside the Hofstra University student center Monday afternoon.

Hours before the start of the debate, Jackson told Newsday he expected most viewers would tune in to the debate because of the “consequential” nature of the election, not just the theatrics of seeing Trump and Clinton face off for the first time.

“I think people have grown tired of the entertainment,” Jackson said. “They want to know ‘What does this election mean to me?’ ”

Jackson said he hoped moderator Lester Holt could “maintain the reins” of the debate to ensure substantive issues were discussed, including student loan debt, increasing wages and “how we relate to our neighbors in Mexico, how we relate to Muslims.”

“If Lester Holt is able to maintain the reins and the debate manages to maintain some logical order, then the outcome is voters get educated, but if it’s just about entertainment, it will be a big waste of people’s time,” Jackson said.

Meanwhile, Hofstra University President Stuart Rabinowitz is proud as punch that his school is hosting its third presidential debate — the first college to do so in three consecutive election cycles.

In a round of interviews in the media hall adjacent to the debate hall, Rabinowitz called Hofstra “Debate U.” and said hosting the Clinton-Trump matchup is “better than a tailgate” party for a college football game.

Hofstra wasn’t originally selected to host a debate this election cycle. It got the opportunity this time after Wright State in Ohio, the original host for Monday night, had to withdraw. Rabinowitz remembered the Friday afternoon he got the call from the Commission on Presidential Debates.

He began with a laugh. “I had just gotten a really bad haircut and so I was really cranky,” Rabinowitz said. “And I had just gotten back to my car and there was email from the commission, a commissioner saying, ‘Please call at your convenience, nothing urgent.’

“So I called and Janet Brown, who is a wonderful person and the executive director, and she said ‘Wright State has withdrawn and you’re the alternate.’ Well, I didn’t remember we were the alternate,” Rabinowitz said, chuckling again. “And I said we’re thrilled and I had to hang up the phone and tell my people to immediately get to work.”

Alan Schroeder, author of the book “Presidential Debates: Risky Business on the Campaign Trail,” said that while “debates are always a spectacle,” interest is particularly high this year because of Trump’s “unpredictable” nature, noting the stream of attacks and zingers the former reality television star unleashed during the GOP primary debates.

“Pretty much everyone in America for those 90 minutes is going to drop whatever they’re doing to watch the debate, and those that don’t probably won’t have anything to talk about the next day, because it’s what everyone will be talking about,” said Schroeder, a journalism professor at Northeastern University in Boston who reviewed more than 50 years of presidential debates for his book.

Long Island’s congressional delegation played political pundits on Hofstra’s campus Monday, sizing up the candidates’ strengths and weaknesses and offering advice for success.

Rep. Steve Israel (D-Huntington) said the key question is whether the public gets substance or a “performance” from Trump. The Republican nominee largely wasn’t pressed for detailed answers in the GOP primary debates where, with up to 10 people onstage at once, candidates rarely went into details about issues.

Israel, arriving just after 1 p.m. to do a round of television interviews on site, called Trump a “natural-born television performer.”

“If the standard is how well you perform, I expect Trump to do well,” Israel said. “If the standard is: What are your ideas for protecting the American people, protecting paychecks and protecting Social Security, then Hillary Clinton is going to rise to that bar.”

Rep. Peter King (R-Seaford) said Clinton’s strength — experience — could work against her.

“Hillary Clinton’s strengths are she has a lot of experience, and she’s knowledgeable,” King said. “At this point in time though, in our political history, people are looking more for change, and the experience can be used against her as being part of the problem rather than the solution”

As for Trump, “he’s unconventional,” King said. “In a time when people are angry and people want change, he symbolizes change. He has a proven record in business, and he speaks a language that people understand.”

Clinton and Trump will field questions from debate moderator Lester Holt, the anchor of “NBC Nightly News,” who last week announced that he would focus his questions on three themes — “the Direction of America, Achieving Prosperity and Securing America.”

The Commission on Presidential Debates, a nonpartisan group that organizes the presidential and vice-presidential debates, said Monday’s debate at the David S. Mack sports complex will focus on each theme in three 30-minute segments with no commercial breaks.

How the candidates “will present themselves to the American people is anyone’s guess,” said commission co-chairman Frank Fahrenkopf in an interview last week with NPR.

“It’s clear that there’s no love between them,” Fahrenkopf said.

Both candidates have taken distinct approaches to preparing for the debate. Clinton has gone through mock debates and studied binders full of policy briefings, according to her campaign, while Trump’s campaign aides have said he has held roundtable discussions on policy issues with his closest campaign advisers, including former New York City Mayor Rudy Giuliani.

“I am going to do my very best to communicate as clearly and fearlessly as I can in the face of the insults and the attacks and the bullying and bigotry that we’ve seen coming from my opponent,” Clinton said in a radio interview last Tuesday with “The Steve Harvey Morning Show.” “I can take that kind of stuff. I’ve been at this. And I understand it’s a contact sport.”

Trump, in an appearance on Fox News’ “The O’Reilly Factor” last Monday said, “If Hillary treats me with respect, I’ll treat her with respect.”

“She can bait me and I can bait her, and we’ll see what happens,” Trump said.

During the campaign, Trump has regularly referred to Clinton as “Crooked Hillary,” and she recently said half of Trump’s supporters belong in a “basket of deplorables.”

The debate on Long Island underscores New York’s central role in this year’s presidential race — Trump, the Manhattan real estate mogul, and Clinton, the state’s former U.S. senator, will have the opportunity to tout their qualifications before a home crowd of nearly 1,000 campaign supporters, Hofstra students and event sponsors.

Hofstra University president Stuart Rabinowitz said that while this is the third consecutive presidential debate the school will host, this year’s bout between Trump and Clinton has generated “much more outside interest.”

The school has granted credentials to more than 5,000 members of the media to cover the debate on-campus, up from 3,000 in 2008 and 2012, Rabinowitz said.

“The core is the same — our students are incredibly excited,” Rabinowitz said, noting that 7,500 students entered the lottery for debate tickets, compared with 6,000 in 2012.

Two of the hundreds of Hofstra students who will attend the debate joined Rabinowitz on CNN Monday morning.

The students, Elena Santo and Jason Carola, may support different candidates, but they agreed on one thing: They want to see more policy talk.

“I think they need to start talking more about policy to really get students engaged because right now it’s just bickering back and forth and I think everybody’s had enough of that,” said Santo, who supports Clinton.

Carola, a Trump supporter, said, “No one’s really focusing on policies.”

“As a whole I think this election specifically is turning the younger generation off of politics,” Carola said, referring to the “media spin” and “doom and gloom” aspects of this election cycle.

Rabinowitz said Hofstra is hosting the debate “for our students.”

“The purpose of this whole thing is to educate and inspire our students to be good citizens,” Rabinowitz said. “What I want them to take away is that they have an opportunity to change things, but they have to do it by voting.”

The debate comes as recent national polls show a tightening race. Nationally, Clinton was ahead by an average of 2.5 percentage points, according to the poll tracking website Real Clear Politics, which calculated the average of major national polls released from Sept. 8 through Sept. 24.

Clinton enters the debate in her adopted home state with a comfortable 21-point lead over fellow New Yorker Trump in New York, according to a poll released by Siena College last week, but trails Trump on Long Island.

A Newsday/News 12/Siena College poll released Thursday showed Trump with a 4 percentage point lead over Clinton among Nassau and Suffolk voters.

About 10,000 demonstrators are expected to descend on the Hempstead campus, prompting Nassau County Police Department officials to deploy more than 1,000 police officers to the school and surrounding area.

Rabinowitz said New York State Police troopers, Secret Service agents and FBI investigators will also be positioned throughout the campus.

Authorities have established a “free speech zone” for protesters on the South Campus, across Hempstead Turnpike, and protesters will be screened for prohibited items including weapons, mace, pepper spray and selfie sticks, said Nassau acting Police Commissioner Thomas Krumpter, at a news conference Wednesday.

The police department has been down this road in 2008 and 2012, so “the executive staff, the chiefs have been here before” and “there’s an institutional plan” in place, Nassau police Det. Lt. Richard LeBrun told News 12 Long Island in an interview Monday morning.

“We have a tremendous amount of resources available today for this,” LeBrun said, adding that providing security for the debate is “a monumental task.”

Nassau County Executive Edward Mangano said law enforcement is “working very, very hard to secure this event.”

“Security is the No. 1 priority of our county,” Mangano said late Monday morning at a news conference.

The extra security presence will cost Nassau taxpayers an estimated $2 million in overtime expenses, county officials said.

Traffic snarls are expected in and around campus Monday due to a number of road closures, including the shutdown of Hempstead Turnpike from Oak Street to Merrick Avenue beginning at 11:30 a.m. through midnight, police officials said.

“We’re sorry about the disruptions,” Rabinowitz said. “ . . . It’s only really 12 hours, then it will all be over.”

With Candice Ferrette, Yancey Roy, Emily Ngo and Scott Eidler