US President Donald Trump scrambled on Wednesday to quell an uproar over his failure to explicitly denounce white supremacist groups during his debate debacle with Joe Biden, who branded his election rival a “national embarrassment”. The bitter adversaries returned to the campaign trail one day after their off-the-rails showdown in Cleveland made headlines less for the substance than for its unrestrained chaos. The toxic shout fest — with Trump constantly interrupting and Biden launching personal attacks — even prompted the overseeing Commission on Presidential Debates to announce it would be imposing new…
