New Jersey Gov. Chris Christie offered a cutting assessment of Hillary Rodham Clinton’s electoral weaknesses recently, telling a group of energy executives that she lacked her husband’s political talents and personal appeal. To punctuate the point, the New Jersey governor mischievously quoted President Barack Obama from a 2008 campaign debate.

"You’re likable enough, Hillary," Christie said, according to two participants.

Gov. Rick Perry of Texas was unsparing in his critique, citing lackluster sales of Clinton’s latest memoir as evidence that Americans have tired of her.

"She’s had a hard time selling books and filling auditoriums," he sniffed to a table of campaign contributors, recalled a guest who heard him.

And Sen. Ted Cruz of Texas has mocked the newly wealthy Clinton as out of touch with working-class voters, calling a country music video produced on her behalf recently so contrived that "I almost fell out of the chair laughing."

The closed-door appraisals from Republicans eyeing the White House in 2016 capture an unseen but intense phase in the emerging presidential campaign: auditions for the job of Clinton slayer.

At political fundraisers and party conferences, over intimate dinners and in casual telephone calls, top contenders for the Republican presidential nomination are constructing an image of Clinton that is relentlessly unappealing: as rusty and unloved, out of step and out of date, damaged and vulnerable.

To win the party’s nomination in a contest over which Clinton looms so large, likely candidates are now jockeying to appeal to several overlapping constituencies, including Republican activists who loathe her, donors who respect and fear her fundraising prowess and party leaders who view her candidacy as a test of their attempts to modernize the Republican brand.

For a candidate to be taken seriously, said Rick Wilson, a Republican consultant, "party leaders need to know that you have a game plan and a path to victory against Hillary."

So to an unusual degree, given that she holds no office, Republican White House hopefuls are pitching their potential candidacies in relation to Clinton’s, building their message around her strengths and weaknesses and making the case for why they are best suited to challenge her, according to those who have spoken to them. These people – donors, operatives and advisers – talked on the condition of anonymity to avoid publicly betraying the confidence of powerful officials who may seek the presidency.

Sen. Rand Paul of Kentucky, for example, has argued that his noninterventionist outlook on foreign policy would offer unique advantages in a head-to-head race against Clinton. His argument: by 2016, Clinton will be viewed as a champion of U.S. military action abroad, alienating younger voters of both parties exhausted by a decade of wars. Given the hawkishness of his likely Republican rivals, he alone, Paul says, can appeal to such disaffected youth.

It is a message Paul has delivered repeatedly, to the likes of David and Charles Koch, the billionaire conservative industrialists, according to a person familiar with their conversations.

Cruz takes an entirely different approach, telling donors that Clinton’s reputation as a moderate, and one who can appeal to elements of the Republican Party, necessitates the selection of a true conservative like himself. He says his brand of raw, unapologetic right-wing politics and policy can excite conservative voters long frustrated, in his telling, by the Republican Party’s tendency to nominate ideologically bland, watered-down figures, like former Gov. Mitt Romney and Sen. John McCain of Arizona.

His message: moderate Republicans rarely win the White House, and their chances would diminish still further in a race against Clinton.

Republicans eyeing the White House are eager to diagnose Clinton’s liabilities and shortcomings, however real or imagined. The biggest of them, they contend, is her deep connection to the Obama administration as secretary of state.

At a dinner for wealthy donors last week in Texas, a guest said, Perry predicted that Clinton would become ensnared in the "Barack Triangle" – a play on the Bermuda Triangle – and was indelibly linked to what Perry said was the president’s mixed economic record, foreign policy struggles and detached governing style. Cruz, latching on to the same theme, has begun referring to the "Clinton-Obama" agenda.

Asked about the Republicans remarks, a spokesman for Clinton, Nick Merrill said, "It’s no secret they attack what they fear."

There may be fear on both sides.

American Bridge, a Democratic organization staffed with Clinton loyalists, published a book this week that compiles unflattering research about her possible Republican rivals, including Christie ("notorious temper," it notes), Sen. Marco Rubio ("flip-flip on immigration"), and Cruz ("controversial Tea Party senator.")

In conversations, the Republican leaders predict a long and messy struggle for Clinton to win over Democrats, casting aside the conventional wisdom that the nomination is hers for the taking. During the meeting with energy executives, held inside a wood-paneled clubhouse in Calgary, Alberta, a few weeks ago, Christie recalled that 2008 was "supposed to be a coronation" for Clinton, too. Of course, it was not, he said.

A recurring message in their conversations with donors, despite polls that show her defeating potential Republican rivals, is the myth of Clinton’s invincibility. After Democrats suffered widespread losses in November’s midterm elections, including of a number of candidates endorsed by Clinton, Gov. Scott Walker of Wisconsin, who is exploring a White House run, described it as a referendum on Clinton. Paul took to Facebook, posting images of defeated candidates emblazoned with the label "Hillary’s Losers."

Some of the critiques have taken on a strikingly personal dimension.

Rubio, among the youngest potential candidates in the Republican field, takes a generational swipe, arguing that Clinton is a relic from a different era. In a meeting with donors recently, he wryly observed that when the Clintons arrived in Washington two decades ago, "cellphones were the size of bricks," said a person told of the conversation. In his forthcoming book, to be published in January, Rubio refers to Clinton as a "20th century politician."

In dissecting Clinton’s personal appeal, or lack thereof, Christie has posited that the more likable candidate almost always prevails in a general election. The implication: his swaggering New Jersey personality would outshine hers.

By laying out a plan of attack against Clinton, the Republicans have revealed just how eager they are to elevate themselves onto the same stage as her: globe-trotting diplomat, sought-after speaker, nominee all-but-in-waiting.

Wilson, the Republican consultant, recalled a candidate who warned donors that Clinton could raise $1 billion in a presidential campaign.

"It’s a viable case," Wilson said. "There is only one or two people who can pull off that kind of financial lift against Hillary."

Two years before the election, some Republicans have already tired of the topic.

Fred V. Malek, a major Republican donor and fundraiser, said that after eight years of Democratic reign at the White House, his party should be drawing up elaborate plans for taking the country in a new direction.

"They shouldn’t," he said, "be thinking about running against Hillary."