What the Facts Are:

Mr. Biden claimed he could immediately pass legislation to create a so-called public option that would allow all Americans to enroll in Medicare.

What Mr. Biden said:

“A Medicare option. We can do that now. I can get that passed. I can get that done, if I’m president of the United States of America.”

This is exaggerated. Mr. Biden tried to argue that his health care plan, which would let Americans sign up for Medicare while leaving private coverage intact, had a more realistic path toward becoming legislation than Mr. Sanders’s Medicare-for-all proposal. In truth, both policies would face long odds in Congress, where Republicans currently hold a majority in the Senate and oppose both ideas. Even if Democrats were to control both houses, the public option would still be far from easy to enact into law: Many wanted to include it in the Affordable Care Act passed under President Barack Obama, but it ultimately fell out of the legislation after intense lobbying from the health insurance industry.

What the Facts Are:

Mr. Biden was wrong on the number of super PACs supporting Mr. Sanders.

What Mr. Biden said:

“You get rid of the nine super PACs?”

This is exaggerated. Mr. Biden was most likely referring to “People Power for Bernie,” a coalition of nine outside advocacy groups backing Mr. Sanders’s candidacy and organizing voter mobilization efforts on his behalf. These groups were labeled “dark money” by Pete Buttigieg, the former Democratic candidate. Most of them others are 501(c)(4) organizations or social welfare nonprofits.

Beyond these groups, Mr. Sanders does have the support of a super PAC of National Nurses United, the country’s largest nurses’ union. It has spent over $750,000 in support of his candidacy, according to the campaign finance watchdog the Center for Responsive Politics. (The center also lists three other super PACs that support Mr. Sanders, but they have spent no money on his behalf.) In contrast, the super PAC supporting Mr. Biden (Unite the Country) was created by his former aides and has spent about $10 million on his behalf.

What the Facts Are:

Mr. Biden said both he and Mr. Sanders embrace the idea of a “green new deal” to address climate change.

What Mr. Biden said:

“We both agree that we have a new green deal to deal with the threat that faces humanity.”

This is mostly true. The Green New Deal is a congressional resolution that lays out an ambitious plan to fight both climate change and economic inequality. It includes a goal of switching to 100 percent wind, solar and other renewable energy by 2030 while providing a federal jobs guarantee and Medicare for all. Mr. Sanders is an original co-sponsor of the Senate version of that resolution, and incorporated many of the elements of the bill into his climate plan, which he also has named for the Green New Deal.

Mr. Biden has said in his climate plan that he believes the Green New Deal “is a crucial framework for meeting the climate challenges we face.” But his plan puts $1.7 trillion into addressing climate change compared with $16 trillion proposed by Mr. Sanders, and sets a slightly later deadline — 2050 — for decarbonizing the economy.

What the facts are:

Mr. Sanders inflated the degree to which he and former President Barack Obama were united in opposition to an immigration bill in 2007.

What Mr. Sanders said:

“That bill was opposed by LULAC, the largest Latino organization in America. They called the guest worker program akin to slavery. The bill was killed because it was a vote on the amendment. I think it was 49 to 48. You know who voted with me? Barack Obama.”