Sens. Michael Hastings (top) and Celina Villanueva (bottom) discuss SB 577.

Illinois charter school advocates and a Chicago Public Schools lobbyist told a largely skeptical Illinois Senate Education Committee on Tuesday that a pending bill supporting charter school employees’ ability to unionize would infringe on the First Amendment rights of charter school administrators and leadership.

Nonetheless, the bill advanced out of the committee in an 11-3 vote.