Arena, who is facing three challengers in his bid for re-election, has worked hard "to ensure that Chicago’s families and taxpayers aren’t adversely affected by the mayor’s anti-education agenda," said Lewis in a statement emailed to union members.
Lewis, who had planned to challenge Emanuel's bid for re-election before being diagnosed in October with a brain tumor, said Arena "will continue his progressive efforts toward creating the city that Chicago’s students deserve.”
Lewis began resuming some of her duties as head of the union last week.
Arena said he was honored to receive CTU's endorsement.
“I will continue to work with Chicago’s teachers to provide high-quality public school options on the Northwest side and throughout Chicago,” Arena said in a statement.
Arena supported the teachers union's 2012 strike, and opposed Emanuel's closure 48 schools in 2013.
Arena was also endorsed by the Chicago Teachers Union in the 2011 aldermanic election, and has been a consistent ally of the 30,000-member union, which has vowed to elect candidates that support its agenda, including a push to make the members of the Chicago Public Schools board elected rather than appointed by Emanuel.
Arena has been one of the aldermen leading the push for an elected school board, and has opposed the mayor's initiatives more than any other alderman, according to a study of council votes by University of Illinois political science professor Dick Simpson.
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