In light of the current Chicago teachers union strike, city officials would be wise to keep in mind that an increasing number of Americans are skeptical of teachers unions' efficacy. 

Since 1976, Gallup has surveyed Americans’ perception of teachers unions' efficacy. In April 1976, 38 percent of Americans believed that teachers unions hurt the quality of public education in the United States. By 2011, nearly half of Americans think teacher unionization has hurt the quality of public education in the United States.

Over this same time period, only roughly a quarter think teachers unions have improved the quality of public education. Interestingly, between 1976 and 1998 when Gallup asked these questions, a declining number of Americans thought teachers unions hurt public education. However, between 1998 and 2011 Americans have become dramatically more skeptical of these unions, leaping from 26 percent in 1998 to 47 percent in 2011.