The results of the voting on a possible strike by the Chicago Teachers Union won’t be available until the beginning of the week.
Even if the CTU membership votes to strike, there will be a period of fact-finding. The earliest a strike would take place, if the members approve the strike, would be March.
Due to the lobbying of anti-union Stand for Children, a strike requires approval by at least 75% of the membership. Jonah Edelman of Stand for Children fought for that approval margin and predicted (wrongly) that the CTU would never get 75% to agree to strike. In 2012, the union vote for a strike was approved by 98% of members voting.
Diane Ravitch's blog 
Many more union locals like Karen Lewis’s Chicago Teachers Union have to follow this example and walk out or else the historic decimation of our public schools under this Democratic President Obama will continue. If teachers join parents in walking-out/opting-out we will get more than a cosmetic re-packaging of NCLB in the 1061 pages of ESSA. We will compel a democratic renewal of public schooling at last, and end the abuses of standardized testing and privatization. Best way to put k-12 and the ugly school war back on the table despite the bipartisan desperation of GOP and Dems to sweep the crimes under the rug.