myrtle beach s.c. grow feud republican front-runner donald trump central rival ted cruz intensify saturday tit-for-tat attack put rest notion debate night fight solitary engagement split two evidence closeness race 2016 republican presidential nomination particularly iowa poll show neck-and-neck battle little two weeks go iowa feb. stag first nominate contest road nov. election trump need victory iowa set win tone campaign keep attempt undermine cruz attempt portray outsider political establishment trump seize report new york time say cruz fail disclose second loan citibank help bankroll 2012 senate campaign time early report cruz disclose loan goldman sachs campaign cruz campaign say failure report loan paperwork error report bank loan trump tell delegate south carolina tea party convention boo trump criticize cruz since cheer cruz speak group early say whatever want trump say response boo report bank loan ... act like robin hood say whatever want .. cruz mention trump tea party event talk reporters fort mill s.c. early day unsparing suggest new york billionaire former reality tv star lack temperament president point frequent twitter assault adversaries say trump attack cruz threat iowa think term commander-in-chief ought someone spring bed tweet frantic response late poll cruz say think american people look commander-in-chief stable steady calm hand keep country safe try prove trump conservative say cruz campaign release video entitle donald trump new york value link 1999 interview trump nbc meet press trump declare favor woman right abortion support gay marriage two candidates clash last republican debate thursday charleston issue new york value trump say cruz insult city absorb sept. 11 2001 attack rebound trump bring issue town hall meet portsmouth n.h. hours schedule address south carolina tea party convention myrtle beach cruz criticism new york say total disgrace report steve holland edit chizu nomiyama sap sponsor coverage independently produce staff reuters news agency grow feud trump cruz escalate attack