The condition of the prediction was met: the post‑election effort to overturn or invalidate the 2020 presidential result did reach the U.S. Supreme Court, most prominently in Texas v. Pennsylvania, which sought to throw out results in four Biden‑won states.

On December 11, 2020, the Court denied Texas’s motion for leave to file a bill of complaint for lack of standing, ending the case. Seven justices explicitly denied leave; Justices Alito and Thomas wrote separately that they would allow Texas to file the complaint but said they “would not grant other relief” and expressed no view on other issues. That means:

• On the jurisdiction/standing question, the split was effectively 7–2 against Texas/Trump (Alito and Thomas differing only on procedure). (en.wikipedia.org)
• On the actual relief Trump and Texas wanted (blocking or overturning the election results), all nine justices rejected it—Alito and Thomas expressly said they would give Texas no relief, and the other seven denied the case outright. (reason.com)

Sacks predicted that if the dispute reached the Supreme Court, the decision against Trump would be at least 7–2 and possibly 8–1 or 9–0. The real outcome was at least 7–2 against Texas/Trump on the key threshold issue and functionally 9–0 against granting them any relief, which fits his predicted range. Therefore, the prediction is right.