With the second impeachment trial of Donald Trump set to begin in the Senate on Feb. 9, many questions are still surrounding the trial. The biggest question is whether or not the trial itself is constitutional, with even legal experts divided on the issue.

The constitutionality of an impeachment trial was voted on in the Senate on Jan. 26, and 45 out of the 50 Republican senators voted that a trial was unconstitutional, since Donald Trump is no longer President. Despite this vote in favor of constitutionality, the trial will still start with a four hour long debate over the constitutionality of the trial.

The strongest argument most Republican senators are using to claim that the trial is unconstitutional comes directly from the Constitution. Article II, Section 4 states that “the President, Vice President, and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high crimes and Misdemeanors.” There is no mention here or anywhere else in the Constitution of individuals being tried after holding a federal office.

However, an individual has gone through an impeachment trial after leaving a federal office, which is a strong argument Democratic senators can use to show that the trial is constitutional, or at least able to occur. In 1876, former Secretary of War William Belknap, who had resigned the same day he was impeached on bribery charges, was still tried in the Senate after a 37-29 vote determined that the trial was constitutional.

Eventually, Belknap was not charged, but every senator agreed that Belknap had accepted bribes. 23 of the 25 senators who voted for acquittal did so because they believed the Senate did not have jurisdiction to put Belknap on trial, saving Belknap from conviction.

Unlike Belknap’s trial, not every senator believes that Trump is guilty of inciting an insurrection on Jan. 6, giving some Republican senators more reasons other than unconstitutionality to vote to not convict Trump, and making it even more likely that Trump will not be convicted.

If the vote over the constitutionality of the impeachment trial is any indicator, as it was in Belknap’s trial, Donald Trump will not receive the two-thirds majority vote needed to be convicted and barred from holding any federal office ever again after the Senate’s 55-45 vote.

However, this impeachment trial can, and most likely will, be used in future impeachments to show that former federal office holders, including the President, can still be held accountable for any wrongdoings they may have committed while in office.