Nikki Haley has suffered a humiliating defeat in the Republican primary in Nevada, despite facing no competition in the absence of Donald Trump.
She received fewer votes than “None of these candidates” by a large margin, the Associated Press projected.
The Nevada governor had advocated voting in this way as a protest because Ms Haley will skip Thursday’s caucuses.
Mr Trump runs unopposed in that vote as he closes in on the presidential nomination.
The fact there are two contests is a result of a dispute between the Republican Party and Democrats in the state legislature.
The legislature passed a law in 2021 to switch from caucus to primary after voting delays in 2020.
A caucus is a vote that requires people to attend in person at a specific time whereas a primary is held in the usual way at a polling station over a number of hours and through early voting.
With 86% of precincts reported, “None” had 63% of Tuesday’s primary votes and Ms Haley had 31%.
But the contest is non-binding because it has been disavowed by the Republican Party.
All the state’s 26 delegates that contribute to the nomination are up for grabs in the caucuses.
So the victory for “none of these candidates” in the primary will have no official impact on the race.
But it reflects the strength of Mr Trump that the backlash against Ms Haley resulted in her effectively losing the vote.
Ms Haley did not campaign in Nevada and chose instead to focus on her home state of South Carolina which votes in just over two weeks. And this rebuke by voters left her team undeterred.
“Even Donald Trump knows that when you play penny slots, the house wins. We didn’t bother to play a game rigged for Trump,” said campaign spokeswoman Olivia Perez-Cubas.
“We’re full steam ahead in South Carolina and beyond.”
Ms Haley could still be declared the victor by the secretary of state’s office if only named candidates are counted, reports the New York Times.
The Republican nominee, almost certain to be Mr Trump, will probably face President Joe Biden in November’s election.
Mr Biden won the Democratic primary in Nevada on Tuesday. (BBC)