Sen. Kamala Harris (R) (D-CA) attacks former Vice President Joe Biden (L) speak as Sen. Bernie Sanders (I-VT) looks on during the second night of the first Democratic presidential debate on June 27, 2019 in Miami, Florida.

Former Vice President Joe Biden and California Sen. Kamala Harris are set to face off again in the second round of Democratic presidential primary debates on July 31.

The rematch comes on the second of two nights of debates, when groups of 10 Democrats vying to unseat President Donald Trump will take the stage in Detroit to lay out their agendas for 2020. The events will be broadcast on CNN.

Harris landed what many considered the most forceful blow of the first debates last month, when she tore into Biden over his comments on the campaign trail about working with segregationist senators.

But the marquee matchup between Biden, who has maintained a steady lead in the polls, and Harris, who made gains after her first debate performance, is hardly the only one to watch.