RELATED Texas Gov. George W. Bush offers David Letterman a t-shirt reading "Dweebs for Bush." Letterman once referred to Bush as a "dweeb" in a Late Show monologue. VIDEO Watch a portion of the Letterman interview (From WBZ.com) EXCERPTS Here are excerpts of Gov. George W. Bush's appearance on David Letterman Wednesday night: Letterman: I know that campaigning is difficult work. How do you look so youthful and rested? Bush: Fake it. Letterman: And that's pretty much how you're going to run the country? Letterman: The road to Washington goes through me, you're aware of that aren't ya? Bush: It's about time you had the heart to invite me. Letterman: In watching the campaign you keep saying 'I'm a uniter, not a divider,' ... Now, what exactly does that mean? Bush: That mean's when it comes time to sew up your chest cavity, we use stitches as opposed to opening it up. JOKE TALLY The number of late-night jokes told about current, former or potential candidates over the last year, according to the Center for Media and Public Affairs. Shows: "Late Show With David Letterman," "The Tonight Show With Jay Leno," "Late Night With Conan O'Brien," "Politically Incorrect With Bill Maher." President Clinton, 1,189 Hillary Rodham Clinton, 329 George W. Bush, 293 Al Gore, 275 Dan Quayle, 162 Pat Buchanan, 63 Steve Forbes, 61 Donald Trump, 59 Rudolph Giuliani, 30 John McCain, 29 Bill Bradley, 28

LOS ANGELES -- Maybe a saxophone would have helped.

Stumping for votes on late-night talk shows, Republican presidential candidates George W. Bush and John McCain tried to entertain but couldn't match Bill Clinton's flashy 1992 musical appearance on "The Arsenio Hall Show."

Their appearances on Letterman and Leno coincided with the release of a report on how often politicians serve as the butt of late-night talk show jokes. Bush and McCain attempted to turn the tables, but their efforts met with only lukewarm results.

"How do you look so youthful and rested?" David Letterman asked Bush during a segment that the Texas governor taped by satellite from St. Louis.

"Fake it," Bush replied.

"And that's pretty much how you're going to run the country?" Letterman countered from New York. Bush smiled.

The Texas governor, who couldn't see Letterman on the satellite link, seemed to have trouble hearing him, too. He grinned nervously and seemed to be fighting silent giggles.

When Letterman asked what he means by saying he's a uniter, not a divider, Bush replied: "That means when it comes time to sew up your chest cavity we use stitches as opposed to opening it up."

Letterman, who is recovering from heart surgery, exchanged uncomprehending shrugs with executive producer Rob Burnett over that line.

McCain appeared relaxed and ready with a series of quips. Most of them, however, were met with silence from "The Tonight Show" audience.

Jay Leno asked McCain if he'd join the Reform Party if he didn't get the GOP nomination.

McCain said he would remain a Republican, although he claimed to have much in common with Minnesota Gov. Jesse Ventura, who quit the Reform Party last month. He quipped that he sometimes wears a feather boa to the Senate, just as Ventura did in the ring as a professional wrestler.

Introduced by Leno as John "Given 'Em Hell" McCain, the Arizona senator indicated his reputation for a hot temper is unfounded.

"Every year in the Senate I win Miss Congeniality," he joked.

Bush returns for more next week, with plans to appear with Leno on the eve of Tuesday's extravaganza of primaries and caucuses -- when voters in more than a dozen states deliver a punch line of their own.

"The shows are fun and the candidates get to prove they are lighthearted," said Matthew Felling of the Center for Media and Public Affairs. "This is crucial in an age where hopefuls are always trying to be the candidate you'd like to grab a drink with."

The center released a study Wednesday documenting how politicians have been used as the butt of late-night jokes over the last year. Hillary Rodham Clinton, running for the Senate, is the No. 1 target for jokesters -- after her husband.

Bush leads among all the presidential candidates, drawing 10 jokes for every one told at McCain's expense. McCain's reputation as a war hero helps insulate him.