In the only presidential debate of the cycle, with the election eight days away, the Republican presidential candidate spoiled his victory by failing to keep his cool amid intense and unexpected pressure from the moderators and his opponent.

The moment was fictional — written in the pages of Jim Lehrer's 1995 novel, The Last Debate — but it echoes the very real concerns of voters who support Donald Trump and fear a similar catastrophe could unfold if he enters his first debate against Hillary Clinton without adequate preparation.

If the Republican presidential nominee agrees to the fall debate schedule, he and Clinton will meet for their first one-on-one battle in Hempstead, N.Y., next month. The initial debate, set to take place at Hofstra University on Sept. 26, has some predicting it will draw more viewers than Super Bowl XLIX.

"It's just got everything going for it," Lehrer himself, who moderated his twelfth debate in 2012, told Bloomberg News in June.

Indeed, when Trump and Clinton take the debate stage they will have arrived from diametrically opposed directions.

Clinton, a skilled debater who spent years defending her husband's policies before championing her own, will enter as the first female presidential nominee of a major political party. "I am drawing on my experience from elementary school," she told Jimmy Kimmel earlier this week when he asked how her debate preparation was going.

The former secretary of state's progress report was a clear dig at Trump, who survived a dozen primary debates by sniping at his opponents in ways that were unusual for a leading presidential candidate. He insinuated that Kentucky Sen. Rand Paul was ugly during an exchange last September, shushed former Florida Gov. Jeb Bush in the final debate before the New Hampshire primary and waged a months-long war against Fox News' Megyn Kelly after she questioned his treatment of women at the first GOP debate.

This time, Trump's loyal supporters hope he will heed their advice and leave his brashness and quick temper at the door.

"I want him to concentrate on speaking about the points that people are interested in like the economy and safety, and I would prefer that he not go after Hillary with personal attacks," Don Panzica of Ashburn, Va., told the Washington Examiner at a Trump campaign rally earlier this month.

Launching personal insults in previous debates has already put Trump at a disadvantage because "the media has now framed that as an impulse problem," explained Kathleen Jamieson, a professor of communication and director of the Annenberg Public Policy Center at the University of Pennsylvania.

"If he engages in the same kind of debate moves that he did in the primaries, it will reinforce public perception that he has problem with impulse control and is disqualifying to be president," she noted.

Maria Burrows, a Trump supporter from Montgomery County, Va., said she had no qualms about Trump's inclination to hurl personal insults when he has previously been asked to clarify or elaborate on his policy prescriptions, but she advised him to take a much different approach with Clinton: "He's got to bring some unscripted moments and energy, but I think a solid mix of that with solid points and plans would give him a good debate."

The difference between a "good debate" and a performance that puts Trump back in the lead less than two months before Election Day will depend on what he is doing to prepare, how often he is practicing and with whom, and how he navigates the gender dynamic that will be illuminated throughout the debate.

Sources close to Trump confirmed this week that the campaign held its first session focused on debate preparation over the weekend in Bedminster, N.J. According to multiple reports, Trump was given briefing binders and videos of Clinton's Senate debates and primary debates against then-Sen. Barack Obama to review and he is being coached by his new campaign manager, Kellyanne Conway.

"Part of it is ongoing briefings because he needs to be kept up to speed more and more, but they also don't want him over-practicing" said one former adviser to Trump, who later insisted that "if anyone can get by without having a sparring partner, it's Mr. Trump."

Alan Schroeder, a journalism professor at Northeastern University and author of Presidential Debates: Risky Business on the Campaign Trail, said history has proven conventional wisdom true: practice makes perfect when it comes to the art of debate.

"I think to go into a general election debate without adequate preparation is really foolhardy and to look back on history, the people who prepared and took it seriously are also those who did quite well," Schroeder told the Examiner.

Take the 1988 vice-presidential debate between Reppublican Dan Quayle and Democrat Lloyd Bentsen for example: Quayle had been advised during his debate prep not to liken his own political experience to that of former President John F. Kennedy, but when it came time for the debate and the moderators thrice asked him if his young age and limited political experience would impair his ability to lead the country if he was forced to take over as president, Quayle rejected the advice and made the comparison anyway.

Bentsen's five-word response — "Senator, you're no Jack Kennedy" — immediately became fodder for late night comedians and a permanent fixture of the modern political lexicon.

Like Quayle's advisers designating JFK comparisons as off-limits, Jamieson said those who have Trump's ear should strongly urge him "not to move into territory that could be perceived as sexist" during the debates. She pushed back against those who said Trump could get away with not practicing on a Clinton stand-in.

"Part of the narrative about Donald Trump is one which suggests that he has responded inappropriately to women specifically in debates," she said, citing his exchanges with Kelly and Carly Fiorina as examples. "So his team should be looking for the most qualified individual they can get to embody Hillary Clinton because there is a gender dynamic in some of Trump's exchanges and they need to make sure they are playing to that weakness."

Schroeder agreed, acknowledging that "one of [Trump's] worst debates was when he was on stage with Fiorina and she just chewed him up."

"That's the kind of thing he needs to be prepared for with Hillary," he warned.

But even if Clinton were to roast Trump as someone with a paper thin understanding of world affairs, one unforgettable jab at the former secretary of state could sway the news cycle and hand him a post-debate polling bounce by reducing the attention paid to her performance. Trump could just as easily bungle his biggest opportunity to convince Americans he has the temperament and leadership skills to be a strong commander in chief by taking one unpleasant dig at Clinton or contradicting something he said minutes prior.

In essence, Trump has the next 32 days to develop a stage presence, policy package and referendum on Clinton that convinces the record number of Americans who are expected to tune in that a candidate "who is widely presumed to be uninformed is, in fact, informed," Jamieson said.

Whether he can do that is its own topic of debate among his supporters.

"From what I know of him, because I'm from New York, he's going to do it his way," affirmed a woman who traveled nearly five hours from the Empire State to hear the billionaire speak in Ashburn earlier this month.