I sit corrected.
FWIW, the legislation passed by the PA Senate has no apparent conflict with the Barnette decision, as it allows students to opt out of reciting the Pledge for reasons of religious or philosophical belief.
What the bill does is to require that schools lead students in reciting the Pledge. They can quite legitimately require this of public schools, assuming the deletion of the “under God” passage. It’s their supposed authority to require nonpublic schools to lead such recitations that I doubt the existence of.
I don’t know about private schools, but for homeschoolers (who may or may not be included in this bill, but I bet they are) failure to comply with state-mandated standards such as this would result in criminal truancy charges against the parents. If you don’t run your homeschool the way the state says you should, it is not a legal school and your children are truant.
Pennsylvania has some fairly strict homeschooling laws, so I would fully expect their regulation of private schools to be at least as severe. It’s like certain state legislatures don’t understand that the whole point of not going to public school is to do things differently than public schools do them. I mean, what if the entire student body opts out of the pledge for religious reasons (say the school is sponsored by the Jehovah’s Witnesses), what is the point of even leading the pledge? And doesn’t the very forced endorsement of the pledge by the administration violate the school’s right to freely teach their religion to their children? Should teachers be forced to contradict themselves in first leading the class in the Pledge, and then teaching the children not to recite it themselves?
The horrible mnemonic that I use to keep those two decisions straight is that in the first one, the Supremes were saying, “You think you’ve got a right to refuse to say the Pledge on religious grounds? Go bite us!!” 