Presidential debate: 7 defining moments in history (+video)

From Ronald Reagan’s one-liner, “There you go again,” to Al Gore’s heavy sighs and eye rolls, zingers and mannerisms can define a presidential debate even more than the candidates’ positions on critical issues. Here is a look back at seven defining debate moments.

2000: George W. Bush vs. Al Gore

The first debate between Texas Gov. George W. Bush and Vice President Gore resulted in another defining gesture – the vice president’s overt sighs and eye rolls during Governor Bush’s responses.

Gore "sighed heavily and repeatedly. He shook his head, frowned, rolled his eyes, and sneered," wrote Lehrer in his book "Tension City.”

“Gore was judged the clear loser in the debate, based almost entirely on his body language and not on what he actually said," he added.

Although Gore tried to change his style for the next two debates, he could not escape the first debate mannerisms – the late-night comedy shows repeatedly mocked them.

Bush also had a defining moment in his quip about Gore’s “fuzzy math.”

“I'm beginning to think not only did he invent the Internet, but he invented the calculator. It's fuzzy math,” Bush said during the first debate.

He used the term “fuzzy math” to deflect Gore’s criticisms of Bush’s plans for tax cuts, Medicare, and how to spend the budget surplus.

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