If there is a Haley voter that will likely vote for Biden, I don’t see that vote as obtainable.
However, voters that were torn between Haley and Trump, but decided for Haley, I do see those as viable for Trump, and he didn’t insult those people.
He specifically insulted liberals that hopped on Haley to skew the vote.
If you're carefully interpreting what he said, that may be true. The problem is many people aren't looking at precisely what he said.
He would have been better off saying something nice about Haley and inviting her to join him. That's how it is always done. Reagan hosted a "unity dinner" to raise funds for the other candidates to pay off their debts, after he secured the nomination in 1980. Reagan knew what he was doing. Trump doesn't.