In 1984, then-Senator Biden supported the Mexico City Policy, which bars taxpayer funding of foreign NGOs that promote or perform abortion as a method of family planning. He was also for years a supporter of the Hyde Amendment, which bars taxpayer funding of elective abortions in the U.S.
In 1981, he voted for a constitutional amendment allowing states to overturn Roe v. Wade; but the next year he voted against such an amendment.
In the 2008 vice presidential debate, he bragged about spearheading "the fight against Judge Bork," a Supreme Court judicial nominee in 1987, warning that Bork would have changed Roe v. Wade if he were confirmed to the Court.
In a 2008 interview with NBC's "Meet the Press," Biden said Roe is "as close to a consensus that can exist in a society as heterogeneous as ours" in that it left decisions on life to the mother in the first trimester of pregnancy, allowed the states some intervention in the second trimester, and that "the weight of the government's input" in the third trimester is that the pregnancy is carried to term.
In a 2012 vice presidential debate, Biden warned that the opposing ticket would appoint judges who would outlaw abortion, and promised that a Democratic administration would not do that.
Biden's 2020 campaign platform calls for the codification of Roe v. Wade as federal law. It also would ensure, as part of a health care "public option," coverage of "a woman's constitutional right to choose."
The topic of gay marriage was also discussed during the debate. Sanders criticized Biden for his vote in favor of the Defense of Marriage Act, which was struck down by the Supreme Court in June 2013. Sanders voted against the bill.
Biden, who has officiated at least one same-sex wedding, proceeded to credit himself for helping to change society's view on gay marriage.
"And by the way, I might add, I'm the first person to go on national television in any administration and say, I supported gay marriage," said Biden. "I supported gay marriage when asked. It started a ripple effect for gay marriage on national television."
The debate, which was moved from Arizona to Washington, DC, due to fears of COVID-19, was held without a studio audience. There are three candidates remaining in the Democratic primary. In addition to Biden and Sanders, Rep. Tulsi Gabbard (D-HI) remains in the race.