I am guilty of some horsing around with the Tulsi topic and have never remotely put her up as a viable candidate or vp.
Having said that, she has her value and in many ways is the opposite of Bootyboy. She is a dem-gone-antiBiden cannon rolling around on the deck of the ship. The crossovers, whether in the form of Bobby Kennedy, Dean Phillips, etc. are enormously valuable to have floating around in the political environment. Buttigieg, on the other hand, has always been and always be just one more dem hack who has not deviated from script one iota.
And yes, Trump has to find a way to get votes beyond his maga base. That has always been so and is not in dispute. What is in dispute is who and how that can done. Sind Trump will not lose his base he does have a chance to soften some things and reach out to suburban women etc. There is an art to that though. You cannot bring in someone such as Haley who is considered to be the moral and political equvalent of Mitt Romney. I mean you can, and maybe Trump will go off the reservation and do so, but it comes with a cost. You want to feel solidarity in your campaign and party the day after you appoint your nominee. Not have the beginning of infighting and republicans dissing the nominee.
The other thing is that has to be noted - Usual Tard with his slideshow probably is a better source- but one of the problems Biden has is that he is already losing more suburban women and the like, and minorities and the like. So Trump does not want to mess up anything that may be working too. Refer back to my comments about Maslows need hiercharchy. ie. these women are down on a lower rung now and are now looking for someone to preserve safety and security. Bottomline is that it comes down to how Trump handles the abortion issue. He has picked up a lot of suburban women on the safety and security concerns but they are still watching him like a hawk on the abortion issue. He can help himself bigtime there or hurt himself. His campaign not mine.
Trump wants to preserve some kind of relationship with Melania, however distant it may be. Don't underestimate her role in picking a VP.