3. G Elliott Morris says in Strength in Numbers that this is poison for the Republicans in the general election, where it won't just be the hard core of MAGA voting.
So, as usual, Trump may have wanted this for his ego. As usual, no one told him no it's stupid and it will backfire. So they'll have a bunch of whackdoodles on the ballot in November whose only credential is top tier bootlicker. Even in Indiana, that won't be very popular in November, by which time the economy will be in hell.