Donald Trump has further cemented his status as frontrunner for the Republican presidential nomination with an easy win in the Michigan primary.
With almost all votes in, Mr Trump has won 68% – against 27% for Nikki Haley.
Ms Haley has not won any of the primary races – which elect a candidate for November’s election.
She has vowed to keep fighting, saying Mr Trump cannot overcome Joe Biden in a presidential election. Mr Biden also won in Michigan despite a protest vote.
Speaking as results began to emerge on Tuesday night, the former UN ambassador told CNN: “We have a country to save”.
But she conceded that “it is very possible” that the Republican party now represented Mr Trump’s views rather than her own political outlook.
Despite Ms Haley’s vow to keep chasing delegates, it is looking increasingly likely that the US is heading towards a rematch in November between Mr Trump and President Biden.
Defeat to Mr Trump in Michigan would mark Ms Haley’s fifth successive loss in the primary contests. At the weekend, Ms Haley was soundly beaten by the 77-year-old in her home state of South Carolina.
And Tuesday’s loss represents a further blow to her presidential ambitions. Americans for Prosperity Action (AFP), a libertarian conservative organisation founded by the billionaire Koch brothers, announced after the South Carolina result that it would no longer spend on her campaign.
In a statement released on Monday night, Mr Trump – who did not travel to Michigan for the ballot – said his campaign’s margin of victory in the state was “greater than we even anticipated”.
He also insisted that auto workers, a major voting bloc in the state, “are with us”. Last month, the United Automobile Workers – a union representing 400,000 workers – endorsed President Biden’s re-election bid.
A candidate can become the Republican nominee by accruing 1,215 delegates by victories in state level primaries, caucuses and conventions.
A majority of delegates in Michigan are due to be awarded on Saturday, when the state’s party holds a convention. Only 16 are determined by the primary vote.
Still more delegates will be up for grabs by the candidates of both parties during Super Tuesday next week.
Mr Biden is largely uncontested in his bid for the Democratic nomination.
Even though he won the Michigan primary easily, thousands of people voted “uncommitted” in the Democratic contest, following a call by activists to send a protest vote over the White House’s support for Israel during the war in Gaza.