Donald Trump has struck out on Twitter at former vice president Joe Biden, who mused days before about beating up the US president if the two were in high school. At a rally hosted by a sexual assault awareness group on 20 March, Biden recalled a recording released during the 2016 presidential campaign of Trump using profanities to refer to lewd behaviour with women. ‘If we were in high school, I’d take him behind the gym and beat the hell out of him,’ Biden said