Trump's obsessions are concerning. He repeatedly seems jealous and insecure when confronted with people who are more popular and liked than him.
But what does McCain's daughter have to say about this?
It's been clear for a while how much she dislikes the Trump family. Her family did not want any of them at the funeral, and her speech there referenced Trump critically. More recently, based on what I've seen on The View, her dislike of him seems to have grown more. That said, on The View, she seems to more recently happily let the other women speak and criticize Trump (and Graham, the Republican Party, etc.) when her father comes up. She seems to encourage them to do so and is in agreement. My guess is she's emotionally tired of talking about it. She still addresses the comments, but perhaps more briefly and indirectly than she did in the past. (That's just my observation based on memory.)
As for suggestions she'll vote Republican in 2020, she's spoken for a while how much distance she feels between herself and the Republican Party. She also makes it clear that she is not happy with the Democratic Party, so I'd be surprised if she voted Democrat. I don't think she knows yet how she'd vote. (A Biden bid seems like it'd tempt her.) But I would be willing to bet that voting for Trump is not something she'll ever consider. I don't think she even voted for him in 2016.
I feel weird commenting and speculating on Meghan McCain in a thread about her father, but since she came up and I'm seeing comments that don't match what I see on The View, I felt I should comment with my own understanding. (That's not to say she doesn't frustrate me with her stances or opinions at times. I just think how much she dislikes Trump and what he represents for the Republican Party is pretty clear.)