The United States Senate acquitted Donald Trump after his impeachment trial. Again. The Democrats' aim, this time, was to disqualify Trump from running for president in 2024.

But the acquittal does not necessarily mean that Trump can be president a second time. While the Senate has the exclusive authority to convict and disqualify Trump after he is impeached, the states have a say in the matter, too. 

Section 3 of the 14th Amendment to the United States Constitution prevents officials from holding office again who have “engaged in insurrection” against the United States. Trump's actions before and on January 6, 2021 — when he incited a deadly mob to assault the United States Capitol — may qualify as insurrection under Section 3. 

This means that individual states, which handle their own electoral processes, can decide whether Trump should be on the ballot. While Congress can pass legislation asserting that Trump violated Section 3, the controversy would not be concrete — and thus subject to final judicial resolution — until states actually ban Trump from the ballot. If enough states did so, the effort could effectively prevent Trump from winning.

If Trump does run, and numerous states ban him, the inevitable litigation would reach the United States Supreme Court. The question before the Justices would be whether Trump's actions amounted to insurrection under Section 3. Instead of a surface-level political fight resolved largely along party lines, as we saw in the Senate, the Supreme Court would render a reasoned constitutional determination. Its decision, moreover, would be based on a fully developed factual record — unlike the thin record before the Senate. (We will learn a lot about what happened before and on January 6th in the coming four years.)

What would the Supreme Court ultimately decide? 

With four years of Joe Biden as president — and perhaps a different composition of Justices as a result — the Supreme Court just might bar Trump from running. We already know the conservative Justices are not afraid to rule against Trump in major election cases. Indeed, they uniformly rejected Trump’s efforts to litigate the 2020 presidential election results.

The prospect that Trump gets banned from the ballot in 2024 has practical implications now. It should deter reasonable Republicans from supporting Trump in the first place: such a risky candidate is not a winning horse. And the threat of litigating whether Trump committed insurrection — and the intense scrutiny on his actions such litigation would bring — may, itself, deter Trump from reentering the fray.

Donald Trump incited a mob to invade the U.S. Capitol to prevent the peaceful transfer of executive power. Despite the gravity of this offense, Republicans in the Senate did not disqualify him from holding office again. The Supreme Court, however, might not be so forgiving. 

William Cooper is a US attorney who has written for the Wall Street Journal, Baltimore Sun, New York Daily News and USA Today, among others.