Editor's note:  Farai Chideya is a journalist and the author of four nonfiction and fiction books, and she blogs at Farai.com. She is a spring 2012 fellow at the Institute of Politics at Harvard's Kennedy School of Government.

By Farai Chideya, Special to CNN

(CNN) – Over President’s Day weekend I traveled from the halls of Harvard to my childhood home in Baltimore, a city far better known for The Wire than its education system. On Saturday night, I heard my mother coach a parent by phone on ways to ensure her child was focused and ready to study. My mother retired as a Baltimore City school teacher several years ago, but she still puts in the time to tutor kids through a program run by a local church. She cared about students then, and she cares now. And, although you would not know it from statements like Rick Santorum's attack decrying the "factories called public schools," dedicated teachers like my mother are not an exception. Not all teachers are great; nor all public schools. But the reason I have been at Harvard, twice – once for my undergraduate education, and now again as a teaching fellow at the Institute of Politics – is based on my parents’ efforts and the excellence that was present in public schools.

That's right – excellence. It's there. A couple of years ago, I had the chance to explain how I benefited from just one of the many extraordinary teachers in my life in a public service ad encouraging people to teach.