CNN — It was only a matter of time before former President Donald Trump went birther on Nikki Haley. After all, the former South Carolina governor and UN Ambassador is a pioneering candidate, the daughter of immigrants from India, and she’s rising in the polls. It’s not only concern about his electoral prospects that’s driving him; Trump’s massive yet fragile ego also feels threatened. So he reached for the most reflexive slur he could find via the far-right news site Gateway Pundit, reposting on Truth Social the false claim that Haley is not constitutionally eligible to be president because her...