Lynne and Dick Cheney discuss Lynne’s new book book, "James Madison: a Life Reconsidered" at the American Enterprise Institute. (Nikki Kahn/The Washington Post)

The question sounded innocuous enough: Did James Madison have an undue influence on George Washington?

“You find that more than once in the early republic,” biographer Lynne Cheney began, as her husband looked on. “The idea that someone is manipulating the president — the president’s really a good guy, but there’s this evil genius — ”

The crowd broke into knowing laughter and then applause. One guy near the front playfully shouted to the couple onstage, “Aren’t you glad you came?”

Lynne smiled and continued: “ — that’s manipulating him. It’s such a good political tactic, if you think about it, because you demean the person who’s the evil genius, and you make the president look weak. So it wasn’t something dreamed up in modern times — it’s been going on for quite a while.”

In one fell swoop, a deft twofer: defending Madison and her husband of almost 50 years.

The Dick and Lynne road show began with a standing ovation Monday evening from the audience at the American Enterprise Institute. The crowd, which included dozens of young conservatives and former Cheney staffers Scooter Libby and David Addington, would have been happy with either half of the Republican power couple. So they were delighted to watch the former vice president interview his wife about her latest biography, “James Madison: A Life Reconsidered.”

It’s unlikely that a new book about Madison would attract crowds if Cheney’s name weren’t on the cover or a different moderator were selected to tease out the best stories about the Founding Fathers. But the two — scheduled to appear together at several book signings, including at the Nixon and Reagan presidential libraries, next week — are a publicist’s dream team.

“We did this for my first book, my memoir, when it came out three years ago,” Dick explained to a reporter. “It’s a lot more fun for the two of us; the audience gets more involved.” Lynne, he said, was always the top student in her class, graduated a semester early, earned a PhD; he got sidetracked by politics. “She’s a very, very serious intellectual.”

This is how their relationship works: “When I write my books, she is sort of an in-house editor. When she writes her books, I get to read it when she’s finished.”

Onstage, the couple— he’s 73, she’s 72 — have that easy, playful banter that comes from decades of marriage. They met in Casper, Wyo., after his father decided to settle there instead of Great Falls, Mont. “If he had picked Montana, I would have never met Lynne, she would have married someone else, and he would have been vice president,” Dick told the audience. Instead, they became high school sweethearts and married on Aug. 29, 1964.

It was, to hear them tell it, a good match. She gave him lots of personal advice and steered clear of the political. “I don’t think I ever offered an opinion about Iraq,” she said. But they shared a common interest in politics and public affairs. From early in their marriage, he would come home and she would want to know everything about his day. “There were times when I sought her advice on certain subjects,” he said, without elaborating.

“It was a way for me to stay plugged in with your life,” she added. “I think it was a generous thing to do and a hard thing to do. Politics can be pretty isolating for the spouse, and I think you did a really nice job.” The only time she was hesitant about his political career was when George W. Bush offered him the spot as his running mate. “She was not enthusiastic,” Dick remembered.

There was very little mention of politics (except for a brief story about Dick’s support of D.C. gun rights) and not a word about the drama that rocked the family last year when daughters Liz and Mary Cheney publicly battled over same-sex marriage during Liz’s abbreviated Senate bid.

Instead, they stuck to Madison, a historical figure who Lynne believes has been misrepresented and underappreciated. She began researching six years ago, fascinated by his role in framing the Constitution and the Bill of Rights. And she was drawn to the epilepsy-like seizures Madison suffered throughout his political life — a struggle that paralleled her husband’s five heart attacks and his heart transplant two years ago.

The fourth president, she argued, has been ignored by historians or tackled after the more glamorous founding fathers. “When they did get to him, they talked about what a shy and sickly fellow he was,” she said. “So you couldn’t imagine how he could have done the grand things that he did — the primary author of the Constitution, the primary author of the Bill of Rights, the first presidency to take the nation to war under the Constitution — and those are just the highlights.”

There was a brief mention of Dolley Madison — beautiful, confident, a great hostess. The marriage was a love story; “Dolley was, however, also a political asset.”

Whether the Cheneys will be remembered as a modern-day power couple is up to historians — but there won’t be much about their personal life to chew on: The couple exchanged letters during college, “but we burned those,” Lynne told the crowd.

The book has received generous reviews, including this from the New York Times: “She clearly brings to life the character and personality of Madison. Apart from Ralph Louis Ketcham’s 1971 life, this is probably the best single-volume biography of Madison that we now have.”

The lines for signed copies snaked around the room; many fans bought multiple copies to give as gifts. Dick stood to the side, signing autographs and chatting with admirers. “You are my ideological hero!” blurted one nervous 20-something.

All things considered, a good book signing.

“Having Dick with me is just wonderful,” Lynne said. “He’s good company on the plane, walking through airports, and good company at events. I think a good marriage usually involves people who are good friends.”