Neither her husband, nor George Clooney, Michelle Obama, Oprah or Al Gore would come close to challenging Hillary Clinton’s polling dominance for the Democratic presidential nomination.

While Republicans wrestle to pick a favourite among 16 candidates, Democratic voters - facing a far smaller field - strongly favour the former first lady and secretary of state, even when presented with a fantasy list of notables, according to a recent Reuters/Ipsos poll of 1,033 Democrats.

Hillary Clinton remains head and shoulders above her legitimate challengers and would thump Bill Clinton in a head-to-head contest if the constitution were amended to allow him to run for a third term.

But potential “first gentleman” and former President Bill is the fantasy candidates who comes closest to his wife, at 26 per cent compared with Hillary’s 51 per cent.

The online poll, which has a credibility interval of 3.5 percentage points, looked at whether any Democrat - experienced politician or not - could pose a threat to Clinton in the primary race.

Oscar-winning actor and liberal activist George Clooney? Just 10 per cent would vote for him.

Liberal darling and retiring “Daily Show” host Jon Stewart? Sixteen per cent. Oprah? 11 per cent.

Current First Lady Michelle Obama was second to Bill Clinton with 20 per cent.

Former Democratic presidential nominees Al Gore and John Kerry were in the 15 per cent range. California Governor Jerry Brown and Julian Castro, the US Secretary for Housing and Urban Development and a former San Antonio mayor, lingered in the six to eight percentage range.

Brittany Tomes, a 21-year-old university student from Levittown, Pennsylvania, said some characters in the poll’s “dream team” were unrealistic. “They need experience of actually being in the government and handling those issues to be trustworthy,” Tomes said. “For the most part, people who are in television don’t really have that background.

“When it comes to the actual Democratic primary race, Reuters/Ipsos’ polling shows Clinton attracting 51.5 per cent of Democratic support as of July 21 vs 21.5 per cent for Senator Bernie Sanders, her nearest opponent.

Thirty-nine per cent of Democrats said they would “enthusiastically” vote for Clinton, while another 21 per cent said they would vote for her because they think she would be most likely to win the presidential race in November 2016. Twenty per cent said they would “definitely not” vote for her. “This is a shrug of the shoulders,” said Larry Sabato, director of the University of Virginia’s Centre for Politics, saying the less-than-full-throated enthusiasm reflects a “bubble-wrapped” and overly staged campaign.

Forty per cent of Democrats said Clinton is a “great” candidate for president, while 39 per cent described her as “adequate”.

Beth Grimes, 62, of Piedmont, West Virginia, said Clinton is the only Democratic candidate she has heard from so far. “I may not even vote because Hillary is the only decent Democrat,” Grimes said. “I don’t really like Hillary. She sways positions too easily.

“If Clinton wins the primary, Democrats are apt to become more enthused about her candidacy once she is pitted against a Republican, Sabato said. “In this very polarised era, it’s the opposition party that generates more enthusiasm - the fact that you’re not the other nominee, you’re not the other party,” he said.