They fall int 3 categories
1. Democrats- People who hate Trump so much that they voted in the GOP primary. Biden will win all of these voters, as unlike other Liberals they will not risk voting 3rd party.
2. Neocon/ Strong foreign policy GOP voters Like Haley for that. Likely to come mostly home to Trump given Biden's Foreign policy. Voting for show that in the future party should not go more isolationist.
3. Other Anti Trump Rs- Likely a group that dislikes both Biden and Trump. Plurality probably voted Biden in 2020 but they still see themselves as Republican. Are a key demographic. Some will vote Biden or the insurrection, court cases, or moral reasons. Others will hold their nose and vote for Trump as the least bad option. Some will sit out the election or vote 3rd party.
I am in the 3rd group (Although I voted desantis rather than Haley in my GOP primary).
I am also a group three Haley voter although I will almost certainly vote for Biden.