Joe Biden secured enough delegates to become the presumptive Democratic nominee in early June 2020 and was formally nominated at the Democratic National Convention in August 2020, heading the ticket with Kamala Harris as his running mate. He remained at the top of the ticket through Election Day on November 3, 2020, ultimately winning the presidency; there was no replacement of Biden as the nominee during the 2020 campaign.

Authoritative sources documenting this include:

• Biden surpassing the delegate threshold and becoming the presumptive nominee in June 2020.
• His formal nomination at the August 2020 Democratic National Convention.
• The certified 2020 general election results listing Joe Biden as the Democratic candidate for president.

No credible record shows a serious health emergency leading to Biden being replaced on the ticket in 2020. Therefore, Sacks’s conditional prediction — that Biden would remain the Democratic nominee and not be replaced at the top of the ticket absent a major health event — matches what actually happened, and is rated right.