berlin support germany center-left social democrats spd slump low level year 10 days election conservative chancellor angela merkel look set win fourth term poll show thursday weekly survey conduct infratest dimap ard television show support merkel cdu/csu bloc unchanged 37 percent spd dip one percentage point 20 percent spd low level since january also score 20 percent party poll low level infratest dimap survey anti-immigration euro-hostile alternative germany afd come 12 percent one point make third-strongest political force business-friendly free democrats fdp follow 9.5 percent radical leave party score percent environmentalist green 7.5 percent support german spd slump low year poll