Haley will never win a GOP primary unless she can somehow find a time machine.
Ds traded a lot of rural, small city, and exurban strength for higher propensity professional voters. These people will turn out for Harris. The R side of the trade (non-degree holding voters) are potent because they turn out en masse for someone like Trump but not for someone like Leah Vukmir. Haley is almost precisely the wrong type of fit for these voters.
The more interesting question is how much does turnout plummet for a boring race like this. Harris might crack 70 million votes.
Who can attract the low propensity voters?
The only person that we know for sure can do this is Trump. But I imagine DeSantis, Noem, Hawley, and Carlson could and maybe even Cotton, R. Scott, and Rubio. But Haley and other voters lab-designed to appeal to Romney-Clinton voters (T. Scott, Hogan) would fail in these areas like Romney did.
The difference between 2008/2012 and 2024 is that Kamala Harris is no Obama. She would still bomb really, really badly in core R areas. But the turnout for her opponent wouldn't be as high.