Updated 10/12/12 – 3:28 p.m.

CHICAGO (CBS) – A day after Jean-Claude Brizard stepped down as head of the Chicago Public Schools, Chicago Teachers Union President Karen Lewis said she thinks Mayor Rahm Emanuel set up Brizard for failure.

Brizard and Mayor Emanuel have insisted Brizard resigned in a “mutual agreement,” because months of speculation about Brizard’s tenure had distracted from the mission of improving schools.

But, as WBBM Newsradio’s Bernie Tafoya reports, Lewis said she believes Brizard was only brought in to carry out Emanuel’s agenda to “blow everything up.”

“I think that was the directive he got,” she said. “I also know he didn’t have his own team, and so what do you expect?”

Asked specifically if she believes Brizard was set up for failure, Lewis said, “I do indeed.”

LISTEN: WBBM Newsradio’s Bernie Tafoya Reports

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CBS 2 Chief Correspondent Jay Levine reports you might call Brizard the mayor’s hatchet man for schools.

He pushed through the longer school day and longer school year, and stood his ground when the union pushed back. He also followed Emanuel’s lead in combative dealings with Lewis and CTU.

But some impressive gains in the classroom – such as record improvements in ACT test scores and a record graduation rate for high schools – were overshadowed by problems in the board room. Much of Brizard’s team was picked for him, and a number of key appointees came and went during his tenure.

In the end, Brizard had to go, too.

“I don’t think he had the appropriate tools,” Lewis said.

She said she thinks Brizard was brought in because he was a person of color who had been an educator, unlike his predecessors at the district, and would do whatever the mayor wanted.

Lewis said Brizard’s appointment “answered the problems that [CPS] CEOs have had in the past – that they were not educators, they were not of this community, they were not black or brown.”

“I think that the mayor wanted to silence those criticisms … so he could do his nefarious agenda,” Lewis said.

Even so, she said she looks forward to having a working relationship with Brizard’s successor, Barbara Byrd-Bennett.

“She is infinitely more mature, and she’s had more experience managing,” she said.

Lewis said she and Byrd-Bennett have already spoken, although she would not reveal details of their conversation. Byrd-Bennett said Lewis was the first person she called after being appointed to the post Thursday night.

Lewis said she has heard that Brizard was told not to have a working relationship with the union, but that incoming Schools CEO Barbara Byrd-Bennett has told her she wants such a relationship, as Lewis said she’s had with CEOs before Brizard.

So, Lewis said, “there are beacons of hope.”

Byrd-Bennett joined the Chicago teacher contract negotiations late in the process, but Lewis said Byrd-Bennett was the only one on the other side of the table who had had classroom experience.