Yahoo News! reports that US president Donald Trump and his team have been quick out of the gate with attacks on opponent Joe Biden’s choice of running mate.

To the surprise of almost no one, Mr Biden chose Californian senator Kamala Harris to be his Vice President, announcing it on Wednesday morning, AEST.

Minutes later, the Trump campaign released an attack ad which revealed the strategy they will deploy in an effort to dissuade voters of supporting the Democratic ticket. That strategy, for now, is to paint the 55-year-old first-term senator as a radical of the far left.

But it’s going to be a very tough sell, according to Dr David Smith, a political scientist from the United States Studies Centre at Sydney University.