But they are on different ones — Ms Haley has already competed in the state’s primary, losing embarrassingly on Tuesday to “none of these candidates”, while Mr Trump is running in Thursday’s caucus, his sole remaining challenger being the obscure Texas pastor Ryan Binkley.
That means the front two will not actually be “against” each other in the Silver State because while Republican voters can choose to participate in both the primary and the caucus, the candidates cannot.
It is a bewildering system that has almost entirely sapped the state’s political relevance for the 2024 primary season.
And it’s all thanks to 2020, when a delay in the results led to many Democratic political leaders in the state, including the late Harry Reid, pushing for the state to abandon the caucus system in favour of a primary.
Only, they didn’t: Nevada now has both.
This is because the state’s Republicans unsuccessfully fought in court to stop the primary from going forward, having opposed the switch. They lost and a judge ruled last year that both contests could take place — the state GOP left to decide how to allocate delegates to the participants on its own.
Unsurprisingly, the Nevada Republican Party chose to award those delegates to the winner of the caucus, which will be Mr Trump, given Ms Haley’s non-participation.
The former president will therefore walk out of the state with up 26 delegates and without having to do much by way of campaigning against his rival.
He has, however, rallied in the Silver State since New Hampshire, not least because it will have a renewed significance come November’s general election.
Mr Trump will hardly have forgotten that Nevada flipped from red to blue in 2020 and helped usher in Joe Biden’s victory.
For that reason, the Biden campaign is already eyeing up the state as well.
His vice president Kamala Harris was in town for a campaign rally recently, held just a short distance away from Mr Trump’s own on the same day.
In Ms Haley’s case, the real battle in the days ahead remains South Carolina.
She hopes her home state, where she served two terms as governor, will provide the stage for a major upset against Mr Trump, without which her claims to be a serious contender for the nomination would begin to look slim indeed.
The front-runner meanwhile continues to maintain a strong lead in both the opinion polls and in the delegate battle, the latter required to secure the nomination itself.
Recognising this, Ms Haley’s campaign is focusing most of its attention on the Palmetto State’s primary on 24 February.
She has vowed to remain in the race past South Carolina whatever happens, although her path to victory remains a steep climb after a second-place finish in New Hamsphire, where she failed to come within single digits of Mr Trump.
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