The next stage in New York’s mayoral race is set to begin. Bill Thompson conceded the Democratic primary to Bill de Blasio, whose populist campaign appears to have won the 40 percent needed to avoid a runoff. Thompson came in second to de Blasio after the Bloomberg-annointed Christine Quinn faded and Anthony Weiner imploded. With de Blasio’s numbers hovering just barely above the 40 percent, Thompson had put off conceding, but changed his mind after a re-canvass of voting machines this weekend. Thompson announced his decision at a conference with de Blasio and Gov. Andrew Cuomo, who has so far stayed out of the race.