I can promise you that your kid will not go to a school that Ms Devos or her children attended.   Vouchers will provide subsidies for the wealthy to attend high level private school,   That voucher will have to pay the full cost of students with limited income. 

It's yet to be seen if a private school can perform equally given the same cross section of students that public schools must deal with.  (We agree that discipline stinks in many schools)

I will not be happy with a dime of my tax money going to religious education of any kind.  I'll have to do another reading of the James Madison papers.

https://www.montpelier.org/learn/religious-freedom

Iowa did provide support for some text books used by private schools and home education.  Nothing for religious material though, although there was no requirement to NOT have religious teaching as well, just not supported by public money.