Quinn won 64.3% in Cook county, the same percentage he got in 2010. But with turnout down, he earned about 79,000 fewer votes out of Cook than last time. That's enough for a few Chicago-centric thinkers to claim, as they always do, that Cook county made the difference. But, even if Quinn had matched his 2010 turnout in Chicago, he still would have lost this election.
Also at Democrats for Progress and DailyKos.