Living here in NH, Trump's support with the party base which is who votes most actively in the primary remains very strong. The main reason Haley got even close was Undeclared voters who voted against him. As one of those voters, that is what I did. The effort fell short and Haley now is on very thin ice. She really has no viable path to beating Trump if she could not win in NH.
Haley had some momentum 2-3 weeks ago, but it was blunted by Scott, Vivek and DeSantis dropping out of the race and endorsing Trump immediately.
Both Vivek & DeSantis attacked Haley more than Trump during their campaigns which IMO was their goal all along; knock her out and have the party rally around Trump before his trials start to reinforce the lie he is being prosecuted solely because he is a threat to Biden's re-election.
The other issue is the Republican party has continued to close ranks around Trump on the state levels and a new group of senators have endorsed Trump in the past 7-10 days.
The party supports Trump in the upcoming Nevada caucus while Haley is running in the primary with Trump absent from the ballot.
The party in SC, Haley's home state, is firmly behind Trump which is another reason Scott endorsed him too.
After those two events, the race should be well over, but if Haley wants to stick it out the next contest is Michigan and the party there is run by Trump loyalists. I doubt Haley will do well there. Even if she can limp into Super Tuesday, there is little chance it will matter.
The RNC, the state and local party organs, the right wing media and the party base decided long ago that Trump would be the nominee regardless of reality, facts, the rule of law, the Constitution or any other concern.
It is a big gamble on their part; if they do not win, the party and base will have no where constructive to go. Trump with their help will likely try to steal the election again which will continue the damage they have done to our country.