It appears that despite being considered a success, last year’s Chicago Teachers Union strike has left the union’s leadership team vulnerable to a challenge from within. A group of CTU members have announced that they are running to replace Karen Lewis, the current union president, and her entire leadership team because they feel that Lewis didn’t leverage the two-week work stoppage well enough to get more concessions from the city.

Included among the list of issues that the challengers feel Lewis punted on was the guarantee that the district wouldn’t be subject to any school closings.

Tanya Saunders-Wolffe – a school counselor who will be gunning directly for Lewis’ job – said during her announcement that while Lewis had all the power thanks to the strike, she didn’t push hard enough to deliver on all the union demands. The Chicago Tribune predicts that Saunders-Wolffe is only the first of the candidates likely to emerge ahead of he May 17 union election, but her statements are a good predictor of the line of attack they will be pursuing in an attempt to unseat the woman who is considered to have led the union to a substantial victory only a few months before.

“We’re still facing closings, firings and givebacks — there were things in the (old) contract that we lost,” Saunders-Wolffe said. She works at Owens Elementary, one of the 129 schools still under consideration by the district for closing this year.

Her running mate, Mark Ochoa, was an officer under the CTU president whom Lewis beat in 2010. Ochoa also works for a school on the district’s preliminary closings list. Saunders-Wolffe said the union should have pressed for a moratorium on school closings when it had thousands of members on the street during the strike.

Lewis and three other members of her leadership team, including Vice President Jesse Sharkey, were recently renominated by the Caucus of Rank-and-File Educators, the CTU sub-group to which they belong, to run for another three-year term this spring. Earlier this week, Sharkey assured the union that the neither Lewis, nor the rest of the union leaders were giving up on fighting school closings, and were still keeping the issue alive with the city.

The coalition that announced its plans Tuesday is made up of members of former CTU President Marilyn Stewart’s United Progressive Caucus; the Pro Active Chicago Teachers Caucus, whose leaders ran CTU until 2004; and independent union members. Members of the ticket said many teachers weren’t entirely in favor of the contract negotiated by the Lewis team during the seven-day strike in September, but only voted for it to get back to the classroom.