Democrats booked six official presidential primary debates and Republicans scheduled nearly twice as many for the 2016 cycle. With each debate there's the possibility that a moment could still be talked about years from now.
Take a look at past memorable debate moments to see that anything really does go.
Donald Trump Spars With Moderator, 2015
U.S. & World
Moderator and candidate faced off on Aug. 6 during the first Republican presidential debate of the 2016 race, when Fox News' Megyn Kelly questioned Donald Trump about his comments about certain women — having called them “fat pigs, dogs, slobs, and disgusting animals.”
Trump responded that America has a problem with political correctness. To Kelly, he said, “I’ve been very nice to you, although I could probably maybe not be, based on the way you have treated me.”
Later, addressing the skirmish with CNN’s Don Lemon, Trump said of Kelly: “You could see there was blood coming out her eyes, blood coming out of her wherever." Many deduced the comment as a reference to menstruation, though Trump later said that he meant her “nose and ears."
Marco Rubio Pounces on 'French Work Week' Dig, 2015
After talk of mutual admiration earlier in the campaign season, former Florida Gov. Jeb Bush broke ranks against Sen. Marco Rubio at the CNBC GOP presidential debate, slamming Rubio's voting record in Congress. But it appeared Rubio got the upper hand.
"Marco, when you signed up for this, this is a six-year term and you should be showing up to work," Bush said. "The Senate, what is it, like a French work week? You get three days where you have to show up."
Rubio countered that Bush had endorsed Sen. John McCain in the 2008 election despite McCain's missed votes while on the stump.
"I don't remember you ever complaining about John McCain's vote record," Rubio said. "The only reason why you're doing it now is because we're running for the same position and someone has convinced you that attacking me is going to help you."
Bernie Sanders Defends Hillary Clinton, 2015
The issue of Hillary Clinton's use of a private email server had dogged her campaign for months when it came up in the first Democratic presidential debate in October.
Vermont Sen. Bernie Sanders was offered a chance to weigh in — and opted to give his chief rival a pass.
"The American people are sick and tired of hearing about your damn emails," Sanders said.
Clinton laughed as she shook Sanders' hand and thanked him.
Richard Nixon Refusing to Wear Makeup, 1960
The winner of the first ever televised presidential debate came down to not what the candidates said, but how they looked, many historians and political observers say. Under the hot lights and harsh cameras, John F. Kennedy used makeup for the event, while Richard Nixon decided against it. The difference resulted in Nixon looking sweaty and sallow, which some have said distracted from his message.
Gerald Ford Saying Eastern Europe was Free from Soviet Union Rule, 1976
Then-President Gerald Ford fumbled during a debate against Jimmy Carter by saying that Eastern Europe was under no influence from the Soviet Union, to the shock of viewers and the moderator. While he later said he meant the U.S. should not recognize the Soviet Union's influence, the feeling at the time was that voters were concerned about Ford's knowledge of foreign affairs.
Ronald Reagan Saying He Paid for the Microphone, 1980
During his 1980 bid to oust Carter, Ronald Reagan was debating with fellow candidates when a moderator started to cut him off. Reagan, who footed the bill for the debate after a regulatory issue prevented the original sponsor to cover the cost, became upset, exclaiming he paid for the microphone, to the applause of the audience.
That wasn't the only time Reagan made waves at a debate during the 1980 election. During the closing remarks of another debate, he asked viewers if they were better off now than they were four years ago — when Carter took over office. He ended up him winning the election.
Four years later, Reagan again turned heads during a 1984 presidential debate. Asked about his older age, Reagan, who was 73, said he wouldn't make age an issue in the campaign against opponent Walter Mondale, quipping that he wouldn't "exploit, for political purposes, his youth and inexperience."
Dukakis' Death Penalty Stance, 1988
Sometimes it's not what a candidate says, but the way they say it that makes headlines. During a 1988 debate between Democrat Michael Dukakis and George H.W. Bush, a moderator asked Dukakis what his stance on the death penalty would be if his wife was raped and killed. While consistent with his record, Dukakis' matter-of-fact response — that he had always been very against the death penalty — came off as too distant to voters, political observers said.
Al Gore's Sighing, 2000
While it may be non-verbal, Al Gore seemed to make his feelings clear by sighing and rolling his eyes throughout his 2000 debate against George W. Bush. Some later said Gore came off as condescending and even bored during the debate.
Obama Calling Clinton "Likable Enough," 2008
When competitors Hillary Clinton and Barack Obama faced off during a 2008 debate, a moderator brought up to Clinton that Obama seemed to be more likable. Clinton responded that while he was, she thought she was well-liked too. Obama responded that she was "likable enough." Some saw it as a joke while others viewed it as a condescending remark.
Dennis Kucinich Saying He Saw a UFO, 2008
In one of the stranger topics brought up during a debate, Democratic Rep. Dennis Kucinich was asked about Shirley McLaine's book, in which she wrote Kucinich saw a UFO outside her home. When asked by a Democratic debate moderator if that was indeed what he saw, Kucinich responded that he did in fact see an "unidentified flying object." “It’s an unidentified flying object, OK, it’s unidentified. I saw something," he said.
Rick Perry's Memory Lapse, 2012
Sometimes a debate gaffe can have a lasting impact on a candidate's campaign. In a 2012 primary debate moment, Texas Gov. Rick Perry sought to list which departments he would cut should he be elected. “It’s three agencies of government that when I get there are gone: Commerce, Education and the, uh, what’s the third one there. Let’s see.." he trailed. Even after prompting from rival Ron Paul —and the moderators — that elusive third department remained on the tip of the then-Texas governor's tongue. “I can’t, the third, sorry. Oops," he said.
Not all talked-about debate moments are limited to those running at the top of the ticket. Over the years, a few vice presidential candidates have also made headlines with unusual debate tactics.
Lloyd Bentsen to Dan Quayle: "You're No Jack Kennedy," 1988
A comparison to a past president brought both vice presidential candidates to the edge in a vice presidential debate. Quayle, who was George H.W. Bush's running mate, was asked about his experience. Going on the defensive, Quayle reasoned he had as much experience as John F. Kennedy did when he ran for president. But his comment struck a nerve with Bentsen, who was Dukakis' running mate. Bentsen brought up his personal friendship with the late president, and told Quayle, "Senator, you're no Jack Kennedy."
James Stockdale Asks, 'Who Am I," 1992
James Stockdale proved sometimes a joke can go awry. The running mate of third-party candidate Ross Perot started off his opening statement in a vice presidential debate asking the audience, "Who Am I? Why am I here?" While it was meant as a joke at his relative anonymity, some viewers were simply reminded they didn't know exactly what he was doing in the election.
Sarah Palin: "Can I Call You Joe?", 2008
Alaska Gov. Sarah Palin took a seemingly friendly approach to debating fellow vice presidential hopeful Joe Biden. At the start of the debate, Palin greeted Biden with a handshake, only to lean in and ask if she could call him Joe during the debate. He obliged, and the moment was caught on camera and played repeatedly over the course of the next few days.