Summary of prediction
Sacks predicted in November 2020 that:

1. Trump’s postelection lawsuits would mostly or entirely fail.
2. If the dispute reached the U.S. Supreme Court, the Court would rule against him.
3. At that point Trump would accept the result (even if he did not formally concede).

1. Lawsuits outcome

• The Trump campaign and allies filed dozens of postelection lawsuits in multiple states; virtually all were dismissed or withdrawn, with no court finding outcome-changing fraud.
  → This part of the prediction was right.

2. Supreme Court outcome

• Key efforts to get the Supreme Court to overturn or invalidate results (e.g., Texas v. Pennsylvania and emergency applications in Pennsylvania cases) were rejected; the Court declined to hear them or dismissed for lack of standing, and did not grant the relief Trump sought.
  → The Court effectively ruled against Trump’s position; this part was right.

3. Did Trump “accept the result”?
This is where interpretation becomes ambiguous:

• Trump never formally conceded and repeatedly and publicly asserted that the 2020 election was “rigged” or “stolen,” including after the Supreme Court rejections and after leaving office.
• He nevertheless did leave office on January 20, 2021, and the constitutional transfer of power to Joe Biden occurred on schedule, with the Trump administration cooperating on some key transition mechanics (e.g., GSA ascertainment in late November 2020, eventual use of transition resources).

Whether that counts as “accepting the result” depends on how you read Sacks’s words:

• If “accept” means de facto compliance with the Supreme Court outcome and the Electoral College result (i.e., no extra-constitutional attempt to stay in power once all legal avenues closed), then the prediction is substantially correct.
• If “accept” means acknowledging the legitimacy of the election outcome (stopping claims of fraud and publicly recognizing Biden as the rightful winner), then the prediction is wrong; Trump has continued to deny the legitimacy of the 2020 result.

Because Sacks explicitly allowed for “he may not concede, but he will accept the result,” and Trump’s subsequent behavior mixed formal compliance with persistent rejection of legitimacy, it is not possible to score this with a single clear label without importing a subjective definition of “accept.”

Conclusion

• Lawsuits mostly/entirely failed: right.
• Supreme Court, if reached, would rule against Trump: right.
• Trump would “accept the result”: depends on whether you focus on behavioral compliance (yes) or public acknowledgment/legitimacy (no).

Given this definitional ambiguity around “accept the result,” the overall assessment is ambiguous.