Harris and Biden may take the headlines – but the Sanders and Warren clash is one to watch in second round of Democratic debates

Politics Explained: Both candidates have sought to become the voice of the left for the party and they are almost neck and neck in the polls

It was the biggest moment in the first Democrat debates, California senator Kamala Harris taking former vice president Joe Biden to task over his political history on race. The type of moment that all of the other 2020 candidates on stage over the two nights would have hoped for.

The “rematch” between the two will be the headline event of the two new debates in Detroit on 30 and 31 July, with the media hoping that Harris strikes another blow, or Biden learns from his first performance and goes out on the attack. With Cory Booker – another candidate who has challenged Biden over his actions on race relations – also on stage for the second debate on Wednesday, there will no doubt be more questions for the former vice president.

Harris’s nationwide poll numbers have dipped from a peak just after her debate performance, from 15.2 per cent to 11.8 per cent, according to an aggregate of July polls by RealClearPolitics. Harris was polling at about 7 per cent before the debates, and will be hoping to make some gains second time around. As for Biden, he is at 29.3 per cent, from 26 per cent just after the debate and 32 per cent before it.