Question: Prior to reestablishing the Deputy Chair of the Democratic National Committee in  February 2017, Tom Perez served in what position from 2009 to 2013? 
Sentence (from "2016 Democratic National Committee email leak"): The leaks contents, which suggested the party's leadership had worked to sabotage Sanders' presidential campaign, prompted the resignation of DNC chair Debbie Wasserman Schultz before the Democratic National Convention.
Relevant evidence: No