WASHINGTON, DC, USA (AP) — Democratic voters feel generally positive about all of their top candidates running for president, but they have only moderate confidence that their party’s nomination process is fair, according to a new poll by The Associated Press-NORC Center for Public Affairs Research.

US voters from across the political spectrum have mixed confidence in the fairness of either party’s system for picking a candidate, but Democrats are especially likely to have doubts about their own party’s process. Among Democratic voters, 41 per cent say they have a great deal or quite a bit of confidence in the Democratic Party’s nomination process, while 34 per cent have moderate confidence and 25 per cent have little to no confidence.

Among Republicans, meanwhile, 61 per cent say they have high confidence in their party’s process, and just 13 per cent have low confidence. President Donald Trump has only nominal opposition in the GOP nomination process, and several state Republican parties have even cancelled holding a primary.

For Democrats, the results reveal early signs of fallout from what’s shaping into a contentious and divisive primary, and sharpen focus on the prospect that the nominee may be chosen in a messy vote at a brokered convention. The anxieties have been exacerbated by a breakdown in the vote count in the kickoff Iowa caucus, an outcome Nevada officials are working to avoid in their caucus Saturday.

Julianne Morgan, 29, of Dayton, Ohio, said her confidence in the Democratic Party’s process was undercut earlier this month when Democrats delayed tabulating the results of the first-in-the-nation Iowa caucuses because of problems with a buggy mobile app.

Her concerns were further exacerbated this week after reading that Senator Elizabeth Warren, a Massachusetts Democrat who is third in the delegate count, was excluded in hypothetical head-to-head matchups against Trump in some recent polls.

“It doesn’t sound like there’s been fair representation for all the candidates,” said Morgan, who is supporting Warren’s candidacy.

The poll builds on AP VoteCast’s earlier findings of distrust in the system among Democrats who voted in last week’s New Hampshire primary.

Some respondents said they worry that an increasingly bitter internal battle for the Democratic nomination could weaken whomever emerges to take on Trump in November. The poll was conducted before White House hopefuls on Wednesday took part in the most contentious debate of the cycle. Democrats are set to host their third 2020 nominating contest on Saturday in Nevada.

“They keep digging at each other,” said Roger Kempton, 85, of Niles, Michigan, a Trump voter in 2016 who said he plans to vote for a Democratic candidate in 2020. “They say beating Trump is the most important thing, but they keeping fighting each other. It’s only making people like myself unhappy with the choices.”

Others raised concerns that the Democrats have hung on too long to the tradition of giving Iowa the first spot on the nominating calendar. Since 1972, the top voter-getter in the Democratic caucuses has gone on to win the nomination in seven of 10 contested races. But only Jimmy Carter in 1976 and Barack Obama in 2008 won the presidency.

“Iowa is not a very diverse state, and I feel like it doesn’t really represent the country well,” said Katie Lewis of Lexington, Kentucky, who backs Vermont Senator Bernie Sanders.

Among Democratic respondents, self-described moderates and conservatives are more likely than liberals to have high confidence that their process is fair, 46 per ent to 34 per cent. Those age 45 and older are also more confident than those who are younger, and non-white Democrats are more confident than white Democrats.

The poll shows that Sanders gets slightly higher ratings nationally from Democratic voters compared to his nearest primary rivals, some of whom remain less well known even within the party.

Seventy-four per cent of Democratic voters say they have a favourable opinion of Sanders, while 67 per cent say that of former Vice-President Joe Biden, 64 per cent for Warren, and 58 per cent for former South Bend, Indiana Mayor Pete Buttigieg. About half of Democrats express favourable opinions of billionaire Mike Bloomberg and Minnesota Senator Amy Klobuchar, while nearly four in 10 say they have a positive opinion of billionaire Tom Steyer.

Many Democratic voters say they don’t know enough to have an opinion of many of the candidates, including Steyer (52 per cent), Klobuchar (39 per cent), Buttigieg (28 per cent), Bloomberg (25 per cent) and Warren (16 per cent).

But about two in 10 Democrats express negative opinions of Biden, Bloomberg, Warren and Sanders.

The more moderate Democrats — Biden, Bloomberg, Buttigieg and Klobuchar — have all raised questions about whether Sanders, 78, a self-described democratic socialist, is too far to the left of the American electorate. Both Sanders and Warren — who support heftier taxes on the wealthy to pay for expanded health care, free college, and other programmes — have been branded by rivals as too liberal.

Biden had poor showings in Iowa and New Hampshire and has faced questions about whether his best days as a politician are in the past.

Bloomberg, the former New York City mayor and billionaire founder of a financial, software, data, and media company, didn’t enter the race until November. Some of his Democratic rivals, as well as Trump, have accused Bloomberg of trying to buy the nomination by pumping in hundreds of millions of dollars of his own fortune to fund campaign ads in the more than a dozen Super Tuesday states and US territories. Those March 3 contests account for more than a third of all delegates at stake.

Bloomberg has also faced criticism for disparaging comments about transgender people, his support of “stop-and-frisk”, a controversial policing strategy that led to disproportionate stops of African Americans and Latinos in the nation’s biggest city, and complaints that he repeatedly made misogynistic comments to women who worked for him in the 1980s and 1990s.

Wanda Gibson, 58, a Democrat from suburban Cincinnati, Ohio, who is undecided about who she’ll support, said that Bloomberg’s backing of stop-and-frisk and his sexist comments were wrong. But she also said that she worried that some Democrats are discounting the possibility that Bloomberg has changed.

“We’ve all done or said something in our past that would not necessarily be politically correct,” said Gibson, who said she is still weighing which Democrat she’ll back. “The problem is that we have Donald Trump, someone who continues to do this stuff daily, sometimes hourly. If someone did something 10 years ago, they can evolve.”