A February election in Chicago as a form of voter suppression
Face it, the Progressive Movement's agenda for cities was to reduce the impact of populism and immigrants on city politics, by making it harder to vote, by moving to at-large voting (which reduces the ability of candidates representing spatially bounded ethnic groups to get elected).
But to schedule a municipal election in February when weather is typically bad, for Chicago'ss Mayor and Council, seems designed to reduce participation, not unlike how DC's April primary can be a form of incumbent protection--albeit not a perfect one.
Although it does seem that regardless, voters are motivated in Chicago, based on early voting results ("Early Voting Ballots Surpass 2011 Election Totals," NBC Chicago).
Even so, Rahm Emanuel is expected to be re-elected ("Chicago Mayor Rahm Emanuel leads in election race," USA Today), in the election scheduled for Tuesday, February 24th, although given the number of challengers, it might mean a run off election, which would be held in April, if Emanuel doesn't receive 50% + one of the vote on Tuesday.