During the presidential debate on Oct. 9, Democratic presidential nominee Hillary Clinton appeared to confirm the authenticity of the emails Wikileaks released on Oct. 7. She clarified that her statement saying politicians need "both a private position and a public position" was an observation from the movie "Lincoln." (The Washington Post)

There are few politicians who are revered by both the left and the right. One of them was invoked by both Hillary Clinton and Donald Trump at the second presidential debate Sunday night.

In response to a question about whether politicians could be "two-faced," Clinton defended having a public and private stance on certain issues by citing President Abraham Lincoln:

As I recall, that was something I said about Abraham Lincoln after having seen the wonderful Steven Spielberg movie called 'Lincoln.' It was a masterclass watching President Lincoln get the Congress to approve the 13th Amendment. It was principled, and it was strategic. And I was making the point that it is hard sometimes to get the Congress to do what you want to do and you have to keep working at it. And yes, President Lincoln was trying to convince some people — he used some arguments. Convincing other people, he used other arguments. That was a great — I thought — a great display of presidential leadership.

The question was spurred by transcripts of speeches the Democratic presidential nominee was paid to give, which WikiLeaks recently published. (A full transcript of the speech in question is available here.)

Throughout Clinton's response in the debate, Trump can be seen shaking his head and making faces on the side. After she finished speaking, he retorted with what sounded like an ad-libbed comeback.

"Now she’s blaming the lie on the late, great Abraham Lincoln. Honest Abe. Honest Abe never lied," the Republican nominee said. "That’s the big difference between Abraham Lincoln and you. That’s a big, big difference. That’s some difference."

Republican presidential nominee Donald Trump said that Abraham Lincoln "never lied," and said that's a "big difference" between Lincoln and Hillary Clinton. (The Washington Post)

Trump's response drew a reaction from the crowd, and The Washington Post's Chris Cillizza ranked the "late, great" line as one of the few "winners" from the second debate.

But who was right? Was our 16th president really the paragon of honesty Trump says he was, someone who never lied? Or was Lincoln a shrewd politician who was not above stretching the truth if it served a political goal?

The short answer is, well, both.

"Lincoln was certainly essentially honest," said Eric Foner, a professor of history at Columbia University who specializes in the Civil War and Reconstruction, slavery and 19th-century America. He is also the author of "The Fiery Trial: Abraham Lincoln and American Slavery," which won a Pulitzer Prize in 2011.

But, while he acquired his "Honest Abe" nickname long before he ran for president, Lincoln and his supporters also realized it was a valuable label to have as "a political brand, so to speak," Foner said. Lincoln was also "a consummate politician," Foner said.

"Abe may not have lied, but as I said, he stretched the truth now and then, no question about it," Foner said. "And it is certainly true, as Clinton noted, that Lincoln frequently had public and private positions that were not entirely identical."

He said the instance Clinton referred to during Sunday's town hall was a prime example: While the House was debating the 13th Amendment in 1865, rumors had reached Washington that negotiations with the Confederacy were about to begin. "Lincoln was afraid this would derail the amendment," Foner said. "He issued a statement saying that no Confederate commissioners were on their way to Washington."

This was true... technically. The Confederate commissioners were actually on their way to Hampton Roads, Va., where Lincoln and Secretary of State William Seward then met with them, Foner said. It's easy to imagine a modern-day fact-checker slapping Lincoln with at least one "Pinocchio" after a claim like that.

James Cornelius, a fellow Lincoln historian and curator at the Lincoln Presidential Library and Museum in Illinois, agreed, though he admits he tends to bristle when people cite films and Googled quotes for their history lessons.

"The question about whether Lincoln did, shall we say, appeal to different members of the House in different terms in order to win their vote is something I believe that nearly all presidents will have done," Cornelius said. "But did Lincoln ever lie? We don’t really have an example of his telling a lie. In that sense, Trump is correct."

Lincoln did not keep a diary, and he and his wife, Mary Todd Lincoln, destroyed their personal letters, he said. Still, historians have combed the many pieces of correspondence left behind from Lincoln and his associates to be able to corroborate Lincoln's reputation as "Honest Abe."

"Lincoln is the most recorded person in the 19th century," Cornelius said. "There is a vast amount of recollected words that Lincoln did or didn't say... Checking those against Lincoln's own later statements pretty well demonstrate that he was honest with himself and honest to others."

In  2011 The Post conducted live chat with Lincoln scholar Harold Holzer, then chairman of the Lincoln Bicentennial Foundation. Holzer debunked a slew of myths about Lincoln but fiercely defended the president's reputation of honesty. An unedited transcript of Holzer's typed response to the chat follows:

i'm really glad you asked this question because it's the one i most regretted omitting from the "big 5."  and this one is gratifying because Lincoln truly deserved the sobriquet "Honest Abe."  He DID work to pay for a book he borrowed that had been damaged by water. He DID pay off the debt accumulated by his failed New Salem store.  His wife DID say he was almost monomaniacal on the subject. Even as a young man, he was the guy most noften recruited to judge horse races and wrestling matches.  impeccable, peerless, gratifying honesty...all his life.  Remarkable.

Cornelius said he did not watch the second presidential debate live on Sunday but he's not surprised Lincoln was invoked. After all, the 16th president has in many ways become a larger-than-life, paradoxical legend appealing to people from most parts of the political spectrum: He was a Republican who didn't get a single vote in the southern states, a northern candidate running on an anti-slavery platform.

"JFK did it, Ronald Reagan did it. Everybody dresses as Lincoln during election time," Cornelius said. "Sometimes it’s more believable than not."

In the 1904 election, Teddy Roosevelt compared himself to Lincoln so much — exaggerating the similarities between his own program and what Lincoln had done — that "he rather irritated Robert Lincoln," Lincoln's oldest son, Cornelius said.

And in 2007, Barack Obama launched his presidential campaign at the Old State Capitol building in Illinois, where Lincoln had delivered his famous "House Divided" speech nearly 150 years before. There was nothing accidental about the site choice.

"Obama practically ran wearing Lincoln's coat," Cornelius said.

Foner said that as a historian, he was pleasantly surprised when Lincoln popped up in the debate Sunday, though he would have preferred "maybe not quite in that way." The complexity of Lincoln's character and evolution can sometimes too easily be collapsed into something one-dimensional, he said.

"One of the qualities of greatness of Lincoln is that he was open-minded and willing to learn.  He was capable of changing his position — on emancipation, or race relations, for example — as conditions changed," Foner wrote. "In a crisis, this is an essential quality in any leader. In my book I call this political and moral growth. Today, Lincoln would be attacked as a 'flip-flopper.'"

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