What actually happened

• In the 2020 elections, Democrats won the presidency and—after the January 5, 2021 Georgia runoffs—effective control of the U.S. Senate with a 50–50 split and Vice President Harris as tie‑breaker, alongside control of the House.
• During approximately the first two years of Biden’s term (January 2021–January 2023), a large set of significant laws were passed and signed, including among others:
  • American Rescue Plan Act of 2021 (major $1.9T COVID relief and social spending package).
  • Infrastructure Investment and Jobs Act (2021), a roughly $1.2T infrastructure bill.
  • Inflation Reduction Act of 2022, with major climate, health‑care, and tax provisions.
  • CHIPS and Science Act of 2022, subsidizing domestic semiconductor manufacturing.
  • PACT Act expanding health benefits for veterans exposed to toxic burn pits.
  • Bipartisan Safer Communities Act, the most significant federal gun‑safety legislation in decades.

Contemporary political reporting and academic commentary widely described Biden’s first‑two‑year legislative record as one of the most substantial for a modern president, especially given the narrow margins in Congress.

Comparing to the prediction

Sacks’ prediction was conditional and qualitative:

1. If Democrats win presidency + Senate, there will be one‑party control and they can pass much legislation; Biden’s first ~two years would be very consequential.
2. If Republicans hold the Senate while Biden wins, we’d see gridlock and a less consequential presidency.

The world that actually occurred is case (1). In that world, there was unified (though narrow) Democratic control and a substantial volume of major legislation was in fact passed and signed in the first two years, and Biden’s presidency is widely regarded as consequential in policy terms compared with the gridlock scenario.

Because the realized conditional outcome matches his described consequences, the prediction is right.