CHICAGO (CBS) — A Chicago Public Schools principal and frequent critic of Rahm Emanuel is blasting the mayor in a campaign ad for Bernie Sanders.

In a politically charged ad in support of Sanders, Blaine Elementary School principal Troy LaRaviere, says, “In Chicago, we have endured a corrupt political system and the chief politician standing in the way of us getting good schools is our mayor.”

LaRaviere says the campaign called him, not surprising because he became a vocal critic of Mayor Rahm Emanuel when he campaigned for his mayoral opponent Chuy Garcia and became an active Sanders supporter last summer.

The call to tape an ad came last Saturday.

“We met in Uptown and they had a camera crew there and they started asking me questions,” LaRaviere said.

No script, no staging, just questions like, “Why do you support Bernie?” and “What makes you think Bernie is the right candidate?”

The campaign liked his answers so much, they produced two ads.

“What Troy is saying and what I am saying is it might be a better idea for the mayor here to start standing up against Wall Street rather than shutting down schools in the city,” Sanders said.

LaRaviere received no money for the ads, just lots of gratitude.

“He hugged me when he saw me so it was cool,” he said.

Bernie Sanders is holding a rally in Chicago at the Auditorium Theatre Monday night. Doors open at 8:30 p.m., and at 6 p.m. there was already a long line to get in, with some waiting since 2 p.m.

Dorothy Tucker