Seattle School board member Cheryl Chow announced today that she will not run for reelection this fall. Chow, a former City Council member, wasn’t known as the most inspirational leader when she ascended to the school board, and her platform was vague. But her heart seemed in the right place, and she appeared to rise to the occasion, for a time serving as board chair. With the advent of several forceful new board members in 2007, Chow seemed to fade into the background, though. At one November meeting over school closures, for instance, she sat virtually silent while most of the other board members peppered Superintendent Maria Goodloe-Johnson with questions. Her departure opens up a seat at a crucial time. Not only is the district grappling with closures and teacher layoffs, but it is drawing up a new assignment plan that will determine which students go to which schools. It’s a messy business that elicits intense emotions from parents. If you thought the debate over closures was ferocious, wait for this, which affects all students, not just those at select schools. And the issues are most intense in Chow’s South End district, where the quality of schools is especially uneven. Whoever steps up to run for her seat, it’s a race to pay attention to.