Hillary Clinton and Donald Trump face off for the first of three high stakes presidential debates. The two US presidential candidates have clashed over jobs, terrorism and race in a bitter television debate. The attacks turned personal as Republican Donald Trump accused his rival Hillary Clinton of not having the right temperament to be president. Meanwhile, Mrs Clinton baited Mr Trump by pointing out that he refuses to release his tax returns. The New York showdown could be the most watched debate in TV history, with up to 100 million viewers.