They are striking against a Democratic mayor. They do not have the backing of President Obama or Education Secretary Arne Duncan. The New York Times editorialized against them. Kevin Drum at Mother Jones understands why people oppose them. Even Harold Meyerson, The Washington Post's self-described democratic socialist, chose to lament disunity in the Democratic party rather than endorse the strike.
A serious attempt to defend the Chicago teachers union is pretty hard to find--and for good reason.
Regarding compensation, most people have heard the numbers by now. Chicago offers one of the highest average teacher salaries in the nation at $76,000 per year, and the retirement benefits--a combined pension and retiree health cost equivalent to 51 percent of salary last year--are also very generous.
Andrew Biggs and I showed that the average public school teacher nationwide receives above-market compensation, and Chicago teachers receive far more than the nationwide average. It's hard to fathom how Chicago teachers could demand a 30 percent wage increase in this context.
Regarding Chicago Mayor Rahm Emanuel's merit pay and teacher evaluation proposals, the union's objections are familiar and weak. The value-added models of teacher effectiveness are explicitly designed to control for outside factors--economic circumstances, home life, achievement level in previous years--that affect student achievement. These models aren't perfect, but they are far better than the old system, which bases pay on essentially nothing that correlates with student achievement.
Details are sketchy, but the Chicago Sun-Times reports today that in negotiations the city has agreed to drastically water down the impact of teacher evaluations. According to the paper, teachers who rate as "needs improvement" would be allowed to "stay at their jobs indefinitely, as long as their scores didn't dramatically decline after the first poor score."
That sounds like a caricature of reform. Let's hope this does not become part of the final settlement.