berlin germany social democrats vow return opposition push theme social justice remake party win less 21 percent vote sunday election bad result post-war history spd party swiftly announce would quit grand coalition serve alongside conservative prime minister angela merkel past four years sunday election give merkel fourth term face difficult coalition talk conservative bloc also small share vote since 1940s nearly half voters reject main party dominate germany since world war two spd particular face difficult task win back support party would continue fight democracy tolerance respect opposition leader martin schulz tell cheer supporters announce decision pull coalition bulwark democracy say germany old political party one buttress european leave 150 years spd struggle differentiate merkel conservatives coalition spd collateral damage dissatisfaction current government say tyson barker expert german politics aspen institute able draw bright line opposition merkel cdu pay price lack enthusiasm tim stuchtey brandenburg institute society security say expect spd move leave election blowout although rule possibility could change mind coalition return without schulz merkel fail find partner become big opposition party spd first task may keep lid anti-immigrant alternative germany afd become first far right group win seat bundestag since 1950s thomas oppermann head spd parliament tell broadcaster phoenix center-left party would shy away legal options block racist statements afd afd oppose immigration deny racist spd hop resurgence schulz 61-year-old bookseller untainted coalition serve brussels head european parliament rather cabinet alongside merkel schulz nomination briefly lift party rat around 30 percent spark hop could win enough seat form leftwing coalition gain evaporate steadily ensue months mild-mannered schulz fail drum voter enthusiasm immigration become particularly polarize issue two years since merkel leave germany border open around million migrants mainly flee war middle east spd back merkel stance welcome refugees schulz tell supporters party headquarter would stay lead party new role opposition call election result bitter loss say spd drive social justice equality workers right important ever give afd gain acknowledge germans divide arrival migrants say party would stick value main party europe traditional leave face crisis confidence recent years leave cast power handful countries britain labour jeremy corbyn tack leave seek support among workers leave behind years stagnant wag government austerity policies elsewhere france spain voters desert new party lead centrists populists jackson janes president american institute contemporary german study say spd suffer dissatisfaction affect mainstream party particular peril face leave party lose track demographic core group among work class voters say spd whole infrastructure build around workers grasp economy change people schulz say party officials would meet monday start remake party say encourage large number young people join party year compare social democratic party europe still firmly ground middle german democracy say 20 21 percent voters insignificant press challenge spd election oct. 15 state low saxony lose one-seat majority coalition partner green trail conservatives poll spd already cede power conservatives twice year state north rhine-westphalia schleswig-holstein german social democrats vow rebuild opposition election drub