"It was such a high mountain to climb," he said.
During his presentation titled "Leadership Lessons from a Presidential Campaign," Plouffe reminded the audience how much was working against Obama during the campaign.
"You cannot understand who he is, who we were as a campaign, without understanding how improbable all of this was," he said. "There has never been a bigger political upset in modern political history, maybe in all of political history. It's hard to reconcile that with now he's on the stage, he's been elected president, he's serving as our president -- but two years ago this seemed like something that would have the lowest of odds and a lot of things would have to happen right."
Plouffe opened by saying it was "Good to be in Indiana ... which is blue on that electoral map for the first time in far too long."
In the 2008 election, Obama became the first Democrat since Lyndon Johnson in 1964 to carry the Hoosier State. Plouffe said Indiana was "the state we wanted most."
Plouffe said Obama came at his campaign in "a very untraditional way." Obama's tack was to "put together a strict plan and stick to it," Plouffe said, which "made the pundits very unhappy.
"Voters rewarded that steadiness," Plouffe said. "(Obama) was the same person for two years. He had a set message and he was very clear about it."
Plouffe said voters seemed to appreciate the way Obama presented himself.
"People were ready to be dealt with as adults, without the same old snarky political tactics," he said.
Plouffe said Obama's presidential opponent John McCain's decision on Sept. 24, 2008, to suspend his campaign in order to work on the proposed U.S. financial system bailout before Congress may have been McCain's undoing.
"He was going to suspend his campaign and look like the patriot," he said. "But the American people want their president to be able to do more than one thing at a time. We knew people would see through that."
Plouffe said the Obama staff "tried to develop a culture in the campaign."
"We went in knowing we were going to do three things," Plouffe said. "We were going to run a grass roots campaign. We were going to trust each other. And we were going to have some fun."
Plouffe said there were mistakes made in the campaign, such as not focusing enough on the economy.
DePauw sophomore David R. Dietz, president of the university's College Democrats and a volunteer for the Obama campaign, introduced Plouffe to the audience of approximately 700 people.
"This election meant many things to many people." Dietz said. "It showed me that if people work together, they can accomplish anything."
Dietz called the Obama campaign "a well-oiled machine," and said "Some of the best political minds of our generation" worked on the campaign. In his estimation, Dietz said, Plouffe was "the unsung hero" of the Obama campaign.
Plouffe lauded the efforts of young voters.
"I think one of the reason younger voters gravitated to Obama -- some of it was generational -- was they thought he was not B.S.ing them. They thought he was being honest with them and understood the future of the country a little better than some of the other candidates. But I think they also got the sense that as a campaign we trusted them, we believed in them, that in many ways our futures and destiny were tied together."
Plouffe said he first began talking with Obama about a possible presidential run after the 2006 congressional elections. Plouffe has worked on numerous political campaigns since 1990, but the Obama campaign marked his first national campaign.
"People forget that two years ago (Obama) wasn't even announced for president," Plouffe said. "And two years before that, he had been a state senator in Illinois. And here he was going up against the strongest front-runner in our party's history in a time of war."
All the narrow odds never ruffled President Obama.
"From the rockiest moment in the campaign, he was the calmest person in the room," Plouffe said.
Plouffe arrived on DePauw's campus early in the day Monday and held a student forum moderated by professor of political science Bruce Stinebrickner and David Bohmer, director of the Eugene S. Pulliam Center for Contemporary Media. He then went to the Pulliam Center to participate in a news conference.