re: Somebody please explain Landry's "school choice" plan to me like I'm 5.

Yep. There will be a run on creating private schools to vacuum up this money. The only benefit they may have over current public schools is they will be able to reject or simply not admit problem students. (Honestly, if public schools had a good way to deal with problem students, they would see improvements overnight.)

Quality existing private schools will either become more selective or expand their facilities. Probably a combination of the two. But they are not going to be doubling or tripling because their model can't be quickly scaled up. It can be done, but would take years.

Honestly, I wish this was structured as a non-refundable tax credit. Or even better, simply offer a refundable property tax credit for parents who send their children to private schools. So, for example, if I pay $4000 in property taxes and send my kid to St. Joseph's paying $13k/year, I get to offset my state taxes by $4k