Illegally. It requires complicity within the administration of whoever cuts the checks (I don't know if that is at the State or local level).
Yep, that's how bad it is.
No it doesn't! The administration doesn't have anything to do with that fee.
It's the unions who make even non-members pay some kind of fee - for what purpose I don't know. I read it somewhere.
But the non-union members will give the CTA a run for their money - they've now formed their own organization.