Presidential hopeful Nikki Haley has suffered an embarrassing loss to “none of these candidates” in Nevada’s primary vote.
Tuesday’s result has been interpreted as a protest staged by Donald Trump-supporting members of the Republican Party.
Mrs Haley is Donald Trump’s last rival in the race to go up against President Biden in November’s US election.
However, with two-thirds of Nevada‘s votes counted, Mrs Haley had 32% while the “none of these candidates” option was on 61%, according to exit pollsters Edison Research.
Mr Trump was not on the ballot and the vote, organised by the state, is not the only primary in Nevada. A separate GOP caucus vote will take place on Thursday.
Ms Haley had decided she would not take part in the caucus vote, which cost $55,000 to participate in, as her team believed it was “rigged”.
Haley campaign manager Betsy Ankney told reporters on Monday: “We have not spent a dime nor an ounce of energy on Nevada. We made the decision early on that we were not going to pay $55,000 to a Trump entity to participate in a process that is rigged for Trump.”
Mr Trump will take part in the Republican Party caucuses and is expected to win, and therefore, pick up the state’s delegates as a result.
The former president had urged supporters to ignore the state’s primary, but many took the chance to protest against Mrs Haley’s refusal to drop out of the national nomination contest.
Nevada’s competing ballots are down to a conflict between the local Republican Party – run by Trump allies – and a state law that forces a primary to be held.
State laws also require that “none of these candidates” is provided as an option in all statewide races so voters can express dissatisfaction with their choices.
“None” – which was added in the post-Watergate era – can’t become a candidate but it came in first in primary congressional contests in 1976 and 1978. It also finished ahead of some candidates in Nevada’s 1980 presidential primaries.
Mr Trump is the overwhelming favourite to win his party’s nomination for November’s election when delegates gather for July’s Republican national convention.
He scored an easy victory in the Iowa and New Hampshire votes last month, but Mrs Haley is continuing her campaign despite opinion polls predicting she will lose in her home state of South Carolina in a few weeks.
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Mr Trump’s other main challenger, Ron DeSantis, dropped out in January after coming a distant second in Iowa.
Meanwhile, with 70% of the ballots counted, Joe Biden appears to have easily won Nevada’s Democratic primary after collecting 90% of the votes.
President Biden faces little opposition and the 81-year-old is all but certain to be chosen as candidate for a second term.