AT first sight it was no contest. On one channel Sarah Palin, the poster-girl of the American right, was wowing audiences with her first routine as a stand-up comedian. On a rival chat show Mitt Romney, the early frontrunner for the Republican nomination in 2012, was delivering such dull fare that his host yawned.

Writing a book and promoting it on late-night television have become an integral part of a presidential campaign launch. It certainly worked for Barack Obama.

For Romney, the tactic seems to have backfired. He may be ahead of Palin in the opinion polls. But 5.8m people tuned in to watch her on the Tonight Show last week, compared with 3.7m for his appearance on the Late Show with David Letterman.

Aides say Romney is positioning himself as the anti-Palin candidate, an experienced leader with a firm grasp of world affairs and economic policy, rather than a maverick who shoots moose and alienates as many voters as she excites.

Getting Palin to do stand-up was a coup for Jay Leno’s Tonight Show. The memoir of the former Alaskan beauty queen catapulted to be John McCain’s running mate has sold 2.2m copies and transformed her from figure of fun into nationwide celebrity.

“The truth is I’m glad I’m not vice-president,” she joked. “I’m glad because I wouldn’t know what to do with all that free time.”

She recalled the closing ceremony of the Winter Olympics in Vancouver, saying: “The minute I saw the giant moose I realised I hadn’t cooked anything for the kids’ dinner.”

While Palin writes glowingly of her husband’s bare chest in her book Going Rogue, Romney’s No Apology: The Case for American Greatness is described as “a blueprint for maintaining America’s global leadership”. The most personal detail in it is that he hates weeding.

“This is not the story of my life, or my personal musings, or development as an individual,” the former Massachusetts governor told The Boston Globe last week. “Those tend to be more popular and the kind of thing people would like to read.”

When Letterman asked about his late father, a former head of American Motors and governor of Michigan, Romney went into a long ramble about his “character and integrity”.

When Leno asked Palin about her father, she replied: “My dad — he’ll tell me what kind of ammunition to use.”

At one point Letterman seemed to yawn as he listened to Romney, a committed Mormon and former investment banker. “I don’t know what any of that means,” he said after one opaque answer.

Romney, who failed to shine in the 2008 primaries to choose his party’s candidate for the White House, was later asked about losing the ratings battle. “I need to get better material,” he quipped.

Last week Romney set off on a 49-city tour to promote the book. “I don’t pretend this is going to be a bestseller,” he said. “I think Sarah Palin, they printed 2m books. We’re printing, like, 100,000.”

The latest poll among Republican supporters puts Romney on 14% with Palin on 11%.

The Republicans are recovering from their defeat in the 2008 presidential elections. But while they predict big victories in November’s mid-term elections, they are concerned at the lack of a figure both charismatic and credible enough for the next presidential race.

As his foray into late-night television proved, Romney will never match Palin for charisma. “Wearing suits with as much boxy individuality as a school uniform does nothing to lessen the sense that Romney was assembled out of widgets, screws and nuts,” said Robin Givhan, a style writer on The Washington Post.

Romney’s “fundamental weakness in 2008 was his seeming discomfort in his public skin”, wrote Ben Smith in Politico. “He’s more at ease now ... his aides believe he’s successfully cast himself as a mature political figure and the ‘adult’ among potential Republican challengers to Obama in 2012.”

With the electorate in clear anti-Washington mood, Romney lacks the outsider card that Palin can play. “I think Sarah Palin is a comic-book character, but to many voters she seems quite authentic while Romney is plastic,” said Steven Clemons of the New America Foundation think tank.

Romney hopes to be seen as a safe pair of hands and many conservative commentators warn that to choose Palin would benefit only Obama.

“Palin is Obama’s preferred opponent,” wrote David Frum, a former speechwriter for George W Bush. “Of course the White House builds her up, of course it seems to play into Palin’s ink-stained hands. The White House is counting on those hands to deliver them ... an easy romp to re-election.”

Neither candidate has yet said whether they will stand. Romney told Fox News: “I’m not going to make that decision until I have to ... and it’ll be after November.”

He was given a boost from the blogging sphere by claims that the Tonight Show manipulated Palin’s performance by adding laughter tracks to cover up audience groans and silence. “I can recount many portions where there was little or no laughter or response,” wrote Michael Stinson, who was at the recording.

“But at the later broadcast they are smoothed over with applause and laughter that were not there at the taping.”