WASHINGTON (AP) - Have you heard the one about the kid who thinks President Barack Obama's job is to "approve this message?" Or the time Mitt Romney compared another presidential run to giving birth?
At presidential fundraisers and rallies, the jokes are easy applause lines for Obama and Romney, a way to entertain supporters before the talk turns to more weighty subjects like Medicare, taxes and foreign policy.
You certainly won't hear the sound of a snare drum or Obama or Romney telling their fans, "I'm here all night, folks! Try the veal."
But during tough economic times, the punch lines lighten the mood and let the candidates poke fun at themselves, their opponents and the odd life of motorcades, basement loading docks and countless handshakes that come with running for president.
Obama often shows a self-deprecating sense of humor on the campaign trail, pointing to his "funny name," the gray hairs that have sprouted on his head and his personal qualities that often find their way into editorial cartoons.
"I confess, I am excited to see Mickey," Obama said at Florida's Walt Disney World last January. "It's always nice to meet a world leader who has bigger ears than me."
Romney tends to take the dead-pan route, playing the role of the buttoned-up former business executive who can deliver a funny one-liner while keeping a straight face.
One of the former Massachusetts governor's favorites combines Bill Clinton's comment about his youthful marijuana use with Romney's extensive private-sector pedigree: "I only spent four years as governor. I didn't inhale," Romney says.
Obama's latest punch line involves Big Bird, Elmo and the fuzzy characters of the long-running children's show "Sesame Street."
During Wednesday's first presidential debate, Romney said he would cut the federal subsidy for PBS because the nation couldn't afford it. Even though "I love Big Bird," Romney said.
The next day, Obama accused Romney of being unwilling to uphold tough regulations on Wall Street but being willing to crack down on Big Bird. "He'll get rid of regulations on Wall Street but he's going to crack down on Sesame Street," Obama said in Madison, Wis. "Thank goodness somebody is finally cracking down on Big Bird ... Elmo has got to watch out."
A good sense of humor has served presidential candidates well in the past. Richard Nixon appeared on "Rowan and Martin's Laugh-In" in 1968, joining in on a gag called "Sock it to Me."
Ronald Reagan deflected attention about his age in a 1984 debate by vowing not to exploit 56-year-old Walter Mondale's "youth and inexperience."
And Clinton traded jokes with late night host Arsenio Hall in 1992 (and wore sunglasses while pumping out a rendition of "Heartbreak Hotel" on his saxophone).
Since July, Obama has been telling supporters a story about a 4-year-old boy named Sammy, whose parents met campaign manager Jim Messina on the presidential trail.
The couple, as the story goes, points to a picture of Obama and ask the boy what the president does. "And the boy thinks for a second and he says, 'He approves this message,'" Obama tells supporters over and over. "So that's what I do. I approve this message."
Whenever Obama invokes Romney at a rally, it typically brings a smattering of boos. Obama's standard response is: "Don't boo - vote," a line that brings laughter and applause.
And he likes to refer to his health care reform law by the name "Obamacare," a word promoted by Republicans. "I don't mind the term because I do care, that's why we passed the bill," Obama says.
Romney always peppers his events with stories about successful entrepreneurs he's met across the country, from a North Carolina furniture maker to an oilman who helped pioneer the drilling of North Dakota's Bakken shale.
Romney always gets laughs when he brings up the sandwich maker who founded Jimmy John's. "Jimmy John" Liautaud, Romney likes to remind his audiences, "graduated second in his class - second from the bottom" but still became a successful businessman.
The former Massachusetts governor occasionally surprises audiences with some "he said what?" moments. During a recent taping of ABC's "Live with Kelly and Michael," Romney held hands with his wife, Ann, and traded stories that don't usually come up in the world of heavily scripted modern presidential campaigns.
Ann Romney, who raised five sons with her husband, repeated a story she typically tells about how, after the 2008 campaign, she told Romney she never wanted him to run for president again.
Romney said his response was: "You know, Ann, you say that after every pregnancy!" But the interview got even more revealing. Mrs. Romney talked about a visit to the White House with Texas first lady Anita Perry that led to them opening a door and finding President George W. Bush in the middle of a massage. Bush later told an embarrassed Mrs. Romney, "I look pretty good, don't I?"
The fun continued when former New York Giants lineman Michael Strahan asked Mrs. Romney, "What does Mitt wear to bed?" prompting her husband to pipe in and say, "I hear the best answer is as little as possible."
Some comedians and satirists say the campaigns could benefit from more light moments. Actor and stand-up comedian Gilbert Gottfried said in an interview that, from his vantage point, the campaign trail humor has been "almost as bad as the banter that goes on with presenters at awards' shows."
Gottfried said he remembered being struck by how Republican Bob Dole showed his sense of humor in commercials and television appearances after his losing 1996 campaign - and how it could have helped him during the campaign.
"I remember watching him, thinking had he done that before, he may have won the election," Gottfried said. "Because during the election he came across as the grumpy old man who is chasing you away from his lawn."
Will Durst, a political satirist, said a sense of humor can serve as a humanizing element for presidential contenders.
He suggested Romney could benefit from making light of some of his so-called "gaffes," offering a line such as: "The campaign is so busy right now my wife is driving both Cadillacs."
"Humor is cathartic. It's very important to us as American people and to our leaders," Durst said. "When we see them enjoying it, I think it gives them hope."