mexico city u.s. vice president joe biden thursday say felt almost oblige say sorry verbal attack mexico u.s. presidential campaign republican front-runner donald trump label mexican migrants rapists drug runners speak alongside mexican president enrique pena nieto visit mexico city biden never mention trump nonetheless loom large proceed lot damage incredibly inaccurate rhetoric would argue feel almost oblige apologize political colleagues say ... mexico mexican people say biden democrat property mogul trump build big early lead race become republican nominee vow make mexico pay wall seal unite state southern neighbor prompt widespread criticism countries want know mr. president heat rhetoric hear competitors nomination president american people .... exact opposite biden add without name trump pena nieto also weigh say build wall isolate oneself 2016 u.s. presidential election nov. 8. event early thursday biden express concern election race say view hold unite state call republican campaign language dangerous damage incredibly ill-advised message come unite state consequence presidential campaign american attitudes toward mexicans mexico generally entire hemisphere place world disturb say trump 69 vow deport 11 million migrants live illegally unite state position share young republican rival texas senator ted cruz 2016 presidential race see reuters blog `` tales trail `` report joanna zuckerman bernstein edit richard chang article fund part sap independently create reuters editorial staff sap editorial involvement creation production biden rue 'damaging tone mexico u.s. presidential race