Image caption Can Mr Gingrich, right, and Mr Huntsman, centre right, live up to the historic debates between Lincoln, centre left, and Douglas, left

Republican presidential hopefuls Newt Gingrich and Jon Huntsman plan to hold a debate styled on the historic 1858 tussles between Abraham Lincoln and Senator Stephen Douglas.

Their campaigns say the debate, to be held on Monday 12 December at St Anselm College in New Hampshire, will provide a detailed exploration of their positions and views for the country.

But are they, the voters and the media capable of an intelligent, detailed debate akin to the 21 hours of speeches and argument Lincoln and Douglas made in 1858?

The 14 Republican debates held so far in 2011 have featured several game-changing moments. They have bolstered Mr Gingrich's candidacy, ended Tim Pawlenty's, and seriously diminished Rick Perry's chances (oops...)..

But the debates have shed less light on the candidates' actual policy positions and on their values, while the moderator-dominated soundbite-ready formats have provided few opportunities for the candidates to challenge one another.

Here is a look at what to expect when perhaps the two most intellectual candidates go head-to-head:

What were the Lincoln-Douglas debates?

In 1858 Abraham Lincoln, a former state lawmaker and one-term congressman, was running in the newly formed Republican party against Democratic Illinois Senator Stephen Douglas.

Douglas was one of the most prominent politicians in the country, and Lincoln challenged him to a series of debates in an effort to raise his profile and show off his oratorical ability.

The seven debates held across the state of Illinois focused largely on the major issue of the day: whether the US should extend slavery into the western territories.

How did those debates differ from 21st Century debates, including those held since May by Republican candidates?

Image caption Newt Gingrich, left, and Jon Huntsman, right, both stand to gain from the debate, analysts say

The debates were three hours long.

They began with an hour-long speech by one candidate, continued with a 90-minute speech by the other, and concluded with a 30-minute rejoinder by the candidate who spoke first.

They had no moderator or media questioner guiding the arguments, and the men were not forced to jam their positions into brief soundbites.

Thus, the two men delved deep into the issue, and over the course of the debates challenged and tested one another's positions and values, says David Zarefsky, professor emeritus of communication studies at Northwestern University, who has written about the Lincoln-Douglas debates.

"There was substantial extended discussion," he says. "Each of them would sometimes make claims without evidence and accusations that were unwarranted, but the issues were really developed in considerable depth."

What were they arguing about?

Image caption Lincoln, shown at the podium, lost the election but was elected president two years later

Lincoln opposed the extension of slavery into the territories, while Douglas favoured allowing voters in each place to decide.

By the end, Lincoln had turned the arguments on the morality of Douglas's position.

"It really had come down to, if you supported the extension of slavery into the territories, if you were willing to allow slavery in the territories, it must be that you didn't think slavery sufficiently immoral," says historian James Oakes of the City University of New York Graduate Center, who has written several books about Lincoln and American slavery.

That's not to say the two men didn't misrepresent the other's position. Each sought to paint the other as an extremist in order to gain ground with the middle of the electorate.

Lincoln tried to make Douglas look like he supported allowing slavery in the northern free states, and Douglas sought to portray Lincoln as a radical abolitionist who favoured - gasp - full political equality for blacks.

Are Mr Gingrich and Mr Huntsman really going to talk for three hours?

The precise format of Monday's debate has not been revealed, but almost certainly not.

One model could be scholastic Lincoln-Douglas style debates, which feature shorter rounds of back-and-forth argument than the two men endured in 1858.

But those competitions nevertheless require in-depth knowledge of the issue, quick thinking, and strong analytical skill, says J Scott Wunn, a veteran high school debate coach and executive director of the National Forensic League.

So what's in it for Mr Gingrich and Mr Huntsman?

Mr Gingrich, the former speaker of the House, has a doctorate in history from Tulane University and styles himself a policy thinker and an intellectual. He owes his current resurgence in the polls in part to his strong performance in this year's debates and wants to showcase his knowledge and public policy experience.

Mr Huntsman, former governor of Utah, has long experience in government and the private sector, and is eager for the exposure.

Previous debates have typically featured as many as eight candidates, and Mr Huntsman has been largely overlooked by moderators who want to hear from those with more support.

And both hope strong performances will drain support from former Massachusetts Governor Mitt Romney, the frontrunner in the upcoming New Hampshire primary election, says Dante Scala, a professor of political science at the University of New Hampshire.

"There's a good upside for both of them," says Prof Scala. "The two have a temporary alliance based on a common opponent."

What are the potential pitfalls?

For one, the men will have to defend their positions and beliefs against challenges from another candidate, perhaps for the first time. And they will have a harder time making statements with no basis in fact or proposing untenable policy ideas.

The previous debates have been "pretty superficial exchanges of assertions," said Prof Zarefsky. "The arguments don't get beyond the first level. There's time to state one's position and to make accusations about another candidate's position but it doesn't go much beyond that."

Also, in the extended discussions in a Lincoln-Douglas style debate, campaigns lose a measure of control over their messages. The candidates will be giving relatively long answers and statements, allowing reporters and news editors much more control over how to tell the story of the debate the next day.

"It's much harder to control which 15 seconds get pulled out of a 30-minute rebuttal," said Isaac Wright, a Democratic campaign consultant.

Will voters watch on Monday?

In 1858, political oratory was a top form of popular entertainment, says Prof Douglas Wilson, co-director of the Lincoln Studies Center at Knox College in Illinois.

Voters had no television, no Facebook and no movies, so when two prominent orators came to town, people gathered from miles around.

They brought sandwiches and drinks, and those who had already made up their minds served as a cheering section, Prof Wilson says.

The American political audience of 2011 is not trained to follow three hours of political debate, says Prof Zarefsky.

This year, the televised Republican debates have been watched with varying degrees of popularity, but it is clear they have altered the course of the campaign.

So who won the Lincoln-Douglas debates?

Douglas won the election - although it is necessary to note that senators in 1858 were not elected by a popular vote but by the state senate.

But Lincoln's masterful performance against a political titan raised his national profile, and the next year, the Republican Party nominated him as its candidate for president.

Douglas ran against him, but Lincoln won, and the rest is history.

"If it hadn't been for those debates, no-one would have known who he was outside of Illinois," says Prof Oakes.