In June, barely six weeks after the city erupted in riots and during the most murderous summer Baltimore has endured in a generation, Mayor Stephanie Rawlings-Blake went to San Francisco to take the oath as president of the U.S. Conference of Mayors. It was all for Baltimore, she pledged: “I intend to use my role as president to advocate for those very specific needs, whether it's food access, education, poverty, or neighborhood investment.” She is the conference’s spokeswoman now and leads its effort to develop an agenda for all American cities. She also serves as secretary of the Democratic National Committee. Now that she won’t be running for re-election, watch out, Hillary . . .