Transcript for Harris, Biden face off again in 2nd Democratic debate
Busy summer for you. The race for the white house and a heated night on the debate stage. Ten more democratic candidates battling it out in Detroit. Front-runner Joe Biden facing his toughest attacks yet on his record of deportations, criminal justice and much more. ABC's Mary Bruce was right there for it all. Mary, so much of this ended up being about Biden and a kamala Harris showdown. Reporter: Hey, Cecilia, voters looking for a rematch last night certainly got it after his lackbusser performance in the first, Joe Biden came prepared for round two and launched a steadfast defense of his record and came ready for a fight but so did his opponents. Kicking off his rematch with senator kamala Harris, Joe Biden had a simple request. Go easy on me, kid. But Harris made it clear she has no plans of easing up hammering him on health care. Your plan does not cover everyone in America. By your staff's and your own you do nothing to hold the insurance companies to task for what they have been doing to American families. Reporter: Biden fired back saying Harris' plan will cost too much and take too long to implement. This idea is a bunch of malarkey what we're talking about here. I don't know what math you do in California but I tell you, that's a lot of money and there will be a deductible. Reporter: After her strong performance in the first debate, Harris was also forced to play defense. Congressman Tulsi gabbard slamming her record as a prosecutor. In the case of those who were on death row, innocent people, you actually blocked evidence from being revealed that would have freed them until you were forced to do so. There is no excuse for that and the people who suffered under your reign as prosecutor, you owe them an apology. My entire career I have been personally opposed to the death penalty and that has never changed. I dare anyone who was in a position to say I will not seek the death penalty. Reporter: It was Biden's record that dominated the night under relentless assault. President Obama's former housing secretary hitting the former vice president on the high rate of deportations under the Obama administration. Mr. Vice president, it looks like one of us has learned the lessons of the past and one of us hasn't. What we need are politicians who actually have some guts on this issue. I have guts enough to say his plan doesn't make sense. Reporter: New York mayor bill de Blasio piling on. If you're debating Donald Trump he's not going to let you off the hook so did you say those depore takes were a good idea or go to the president and say, there is a mistake, we shouldn't do it, which one? I was vice president. I am not the president. I keep my recommendation to him in private or the raniere criminal justice reform, booker and Biden going head-to-head. If you want to compare records and frankly I'm shocked that you do, I'm happy to do that. There is nothing done for the entire eight years he was mayor. There was nothing done to deal with the police department that was corrupt? There is a saying in my community. You're dipping into kool-aid and you don't even know the flavor. You need to come to the city and see the reforms we put in place. Reporter: The candidates spent more time attacking each other than the president but senator Kirsten Gillibrand getting a laugh with this shot at trump. The first thing that I'm going to do when I'm president is I'm going to Clorox the oval office. Reporter: By the end of the night Biden was brushing off the attacks. Well, I love your affection for me. You spent a lot of time with me. Reporter: Now, Biden did have a few flubs including in the final moments where he urged his supporters to go to joe30330. Now, it's not clear if he was trying to reference a phone number so supporters could get text messages about his campaign or direct them to a website but that is not his campaign's website and it appears a Pete buttigieg supporter scooped up that url. You mentioned that comment telling kamala Harris go easy on me, kid, before the debate even started. That's generating some controversy this morning and Harris was kind of forced to respond. Reporter: Yeah, look, Joe Biden certainly has his own signature folksy style but was criticized. A lot saw it as patronizing and her campaign was quick to point out and question the former vice president calling the 54-year-old senator a kid but Harris says she was not offended by it adding nobody is going to define me. Another thing we saw, Mary, some of those lower tier candidates really trying to distinguish themselves especially ahead of this next debate qualifying for this next debate, ABC's debate next month trying to gain traction. Reporter: Yes, Cecilia, she's are a chance for lesser known candidates to try to have one of those breakthrough moments. We saw Tulsi gabbard having some success with that when she grabbed the spotlight and challenged kamala Harris, in fact, on Google she was the most searched competitor of the night but a lot of people, it seems, were simply looking to know who was up and who was down on Google at one point and over 2,000% increase over the search of who is winning this debate? They want that answer. Thanks so much.
This transcript has been automatically generated and may not be 100% accurate.