Getting Ferguson Majority to Show Its Clout at Polls

Down the street from where the body of Michael Brown lay for hours after he was shot three weeks ago, volunteers have appeared beside folding tables under fierce sunshine to sign up new voters. On West Florissant Avenue, the site of sometimes violent nighttime protests for two weeks, voter-registration tents popped up during the day and figures like the Rev. Jesse L. Jackson Sr. lectured about the power of the vote.

In this small city, which is two-thirds African-American but has mostly white elected leaders, only 12 percent of registered...