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He was exhausted, sweaty and pale. His shirt was one size too big and five shades too light. And after a full day of campaigning, he was tired and anxious, all things a candidate does not want to be during his first televised presidential debate.

It was this sickly demeanor that made Republican Vice President Richard Nixon's first televised presidential debate appearance go down in history as one of the worst. And in tapes released exclusively to ABC News today, Nixon was poignantly aware of how poor his performance was in that 1960 presidential debate against Massachusetts Sen. John F. Kennedy.

Tune in to ABCNews.com on Wednesday for livestreaming coverage of the first 2012 Presidential Debate from Denver, Colo. Coverage kicks off with ABC News' live preview show at noon, and full debate coverage begins at 8 p.m.

In a conversation between Nixon and his White House Chief of Staff Bob Haldeman recorded in 1971 during Nixon's first term as president, Nixon recounts how unprepared he was for that debate, which 77 million Americans tuned in to see.

"Remember, even on the first debate. We made the mistake of not [preparing] for that one. Well, or-we got prepared. Worked like hell," Nixon says in a tape unearthed today by Nixon scholar Ken Hughes. "[We were] running the goddamn schedule so hard, we didn't learn from the other-we're never going to make that mistake again."

The conversation started with the two men discussing the day-long preparation that First Lady Pat Nixon went through for a television interview that day.

"You know, it's funny. She would be perfectly willing to do a day's work to get everything organized to put on a reception for 5,000 people at the White House and stand there and shake hands with them and think that was a very worthwhile thing to do," Haldeman says. "But to do the same day's work for a television thing, you kind of tend to feel it's useless, because [ unclear] interviewer. You forget the fact that all those millions of people see it."

"You know something?" Nixon responds. "By God, I did not understand this enough in '60. You know, I hated to do television shows."

"I was totally wrong," the president concludes.

Nixon, who lost to Kennedy by a fraction of a percentage in the 1960 election, refused to debate during his second campaign for the White House in 1968. And in 1972 when his Democratic rival George McGovern, a senator from South Dakota, challenged him to a debate, the incumbent president refused.

In another previously-unreleased taped conversation, Nixon and Haldeman came up with two excuses for why the president would not take McGovern up on his debate challenge.

"The differences between these two candidates are so great and so clear that no debate is needed to bring out those differences," Nixon says, dictating what the White House response should be in a taped conversation at Camp David on July 22, 1972.

"Particularly with the international situation and the very sensitive matters that are being discussed, that debate would not serve the national interest," Nixon added.

The main topic of the 1972 election was the Vietnam War. McGovern was fiercely anti-war and pledged to immediately pull all U.S. forces out of Vietnam.

Hughes, the presidential researcher at the University of Virginia's Miller Center, said Nixon's predecessor Lyndon B. Johnson also used the national security excuse. The argument was that because of the information he as president had access to about the Vietnam War, participating in a televised debate could threaten national security because he might accidently say something confidential.

In the newly released tape, Haldeman encourages Nixon to use that excuse to get out of debating McGovern.

"Somebody ought to go out and say that for God's sake with McGovern's total irresponsibility and his running around talking to North Vietnamese that the president would be out of his mind and would be jeopardizing national security to debate," Haldeman says.

Ultimately, Nixon and McGovern did not appear together on a debate stage. Hughes said there was almost no controversy over Nixon's decision to sit it out.

"The expectation was that if an incumbent president did not have to debate he wouldn't," Hughes said.

And because Nixon was dominating McGovern in the polls, "no one really pressured Nixon to take part in this."

Nixon went on to beat McGovern in one of the biggest landslide elections in history, winning 61 percent of the popular vote and 97 percent of the electoral college. McGovern only won one state: Massachusetts.