berlin chancellor angela merkel warn german voters wednesday risk allow untested left-wing alliance take power month national election urge stick turbulent time less three weeks sept. 24 vote politicians media germany turn attention possible coalitions could form election single party expect emerge clear majority merkel 63 lead grand coalition conservatives left-leaning social democrats spd tie-up neither want repeat vote seek fourth term merkel stress credentials global stateswoman country afford experiment especially turbulent time tell rally torgau 70 miles 120 km south berlin state saxony merkel speak cacophony jeer whistle protesters feature many rally resentment persist decision 2015 open germany border hundreds thousands refugees flee war syria iraq decision help rise anti-immigrant alternative germany afd party punish conservatives regional vote last year since bounce back national election likely return fracture parliament due rise afd set enter bundestag first time expect return pro-business free democrats fdp could make coalitions hard form merkel want avoid outflank coalition spd far-left linke environmentalist green hold exploratory talk possibility join force so-called red-red-green r2g coalition say red-red-green would bad country tell rally future need stability security televise debate spd leader martin schulz sunday merkel challenge rule coalition linke party refuse red-red-green combination untested federal level though three party team take control berlin city government opinion poll release wednesday put support merkel conservatives 38.5 percent ahead spd 24 percent green 7.5 percent free democrats 10 percent linke afd percent resentment merkel open-door policy run particularly high eastern germany also boo rally west ludwigshafen 45 miles 70 km south frankfurt last week germans need take care us vincent raap 18-year-old start apprenticeship machine operator say ludwigshafen rally three time apprenticeship apply give foreigners instead say hold sign say merkel must go merkel tell voters 'do n't experiment leave