The Center for Governmental Research and a local opinion-research firm, Metrix Matrix, are polling a sample of Rochester residents this week on mayoral control. A previous poll, commissioned by a coalition of mayoral-control opponents, surveyed only parents, so this poll is taking the pulse of a broader public.

Both polls, I think, have some merit. Parents are more familiar and more intimately involved with Rochester schools, so knowing how they feel about a major change is important. Parents and students aren't the only people with a stake in the success of the schools, though, so the CGR-MM poll is important, too.

The thing is, there's been no full public discussion about mayoral control.

Mayoral control's sponsor, Bob Duffy, hasn't yet explained forcefully why he thinks children will get a better education if the superintendent reports to him rather than to the School Board.

And so opponents, who are the most fired up, have framed the debate, much as Republicans have framed the national discussion about health-care reform.

The School Board says Duffy's real goal is to get control of the district's revenue. The district's employee unions think what he has in mind is gutting the district's staff. And some African-American community leaders have launched the emotion-laden argument that mayoral control takes away the public's right to vote - something Americans, most particularly African Americans, have shed blood to win.

This new poll will test how effective the opponents' message has been.

CGR and Metrix Matrix say they'll announce the poll results by the end of March. We should all keep in mind, though, that whatever the results, they're just a snapshot of public opinion, taken at a particular moment in this debate about a particularly complex topic.

Maybe somebody will conduct a second poll after there's been a thorough debate.