Presidential candidate Joe Biden hit back hard during Thursday night's Democratic primary debate after fellow Democratic 2020 contenders attacked the Obama administration's immigration policies, saying comparisons to the Trump administration are "outrageous.""We didn't lock people up in cages. We didn't separate families. We didn't do all of those," the former vice president said.The Obama administration deported at least 3 million undocumented immigrants, riling immigration advocates and earning him the nickname "deporter in chief.""The President did that best thing that was able to be done at the time," Biden said."How about you," ABC moderator Jorge Ramos followed up."I am the vice president of the United States," Biden responded.Biden was previously challenged on former president Barack Obama's immigration record by New York Mayor Bill de Blasio during the July 31 Democratic debate."You were vice president of the United States. I didn't hear whether you tried to stop them or not using your power, your influence, in the White House," de Blasio asked Biden. "Did you think it was a good idea or did you think it was something that needed to be stopped?""The President came along, and he's the guy that came up with the idea - first time ever - of dealing with the Dreamers," Biden shot back, referring to Obama's Deferred Action for Childhood Arrivals program. "To compare him to Donald Trump, I think, is absolutely bizarre."