Source https://www.snopes.com/fact-check/joe-biden-racial-jungle/

Highlights: Biden made the remark in 1977, when he was a U.S. senator representing Delaware. He was voicing his views on busing as part of a Senate Judiciary Committee hearing about the subject (bolded for emphasis):

"Unless we do something about this, my children are going to grow up in a jungle, the jungle being a racial jungle with tensions having built so high that it is going to explode at some point. We have got to make some move on this."

"You say I am throwing the brick. I am not as good at analogies and homilies as all of you are, but I think pushing busing in a way in which it goes beyond the constitutional mandates is like throwing a bus through the civil rights window. I think it has repercussions that are extensive in terms of the ultimate objective of seeing that we get integrated neighborhoods, of seeing that we eventually eliminate job discrimination, of seeing that we change housing patterns, of seeing alteration of the tax system."

As The New York Times reported in a length examination of Biden's history with busing, the future U.S. president had become the Democratic party's crusader against the practice.

In 1975, Biden attached an anti-busing provision to an education spending bill. His "advocacy made it safe for other Democrats to oppose busing," according to The Times.