Transcript for Tough challenges ahead for the 2020 Democratic candidates
Rachel, thank you. Now to the democratic hopefuls in the 2020 race for president. Nearly the full field of candidates descending on south Carolina this weekend. Some confronted by their first major challenges of the Joe Biden drawing much of the attention for his stumble on race. Pete buttigieg returning to the field after facing protesters at home. Tara Palmeri is in south Carolina. Reporter: Tonight some democratic candidates making their pitch to black voters in South Carolina. Facing some of their toughest challenges yet. Joe Biden coming under fire for his comments on working with segregational senators in the past. Corey book calling on Biden to apologize. The two sharing a hug in south Carolina at a fish fry. Do you think Joe Biden should apologize? If Corey is satisfied I'm satisfied. Reporter: Some still say Biden's response falls short. He's going to have to make a decision whether or not he apologizes. I've been very clear. I think his perspective on this is misinformed. Reporter: Voters we spoke to say they'll look past it. If Biden can win in 2020. It is 150% important that we choose a democratic candidate that can beat trump. I think Biden is our best chance. Reporter: A community crisis pulling mayor Pete buttigieg off the campaign tram and back to South Bend. The mayor confronted by protesters demanding answers after a fatal shooting of a black man by a white police Did you ask me if black lives matter? Of course black lives matter. Then fire your cops. Reporter: The mayor back in South Carolina. Mayor Pete, how could you unite the country when south Reporter: Not answering the question, but saying it's about problems back home. My community is full of people who believe in safety and justice. We will heal and we will come stronger in the broken places. Tara Palmeri joins us now. Thousands of South Carolina Democrats showing up for those events. The candidates meeting voters but also prepping for their first big test next week. Reporter: That's right, Tom. Right behind me mayor Pete is getting a test from voters tonight in South Carolina. In less than a week 20 democratic candidates will be in Miami for their first democratic debate over two days. Tom? We'll be looking forward to the debates. Tara, thank you. Senator Cory booker will be the guest on tomorrow's "This week." Tune in.
This transcript has been automatically generated and may not be 100% accurate.