There is no official to preside over such an unconstitutional trial. The Constitution stipulates that when The President (not The Ex-President) is tried, then the presiding officer is The Chief Justice of the SCOTUS. Who would preside? Kamala Harris? ----No----it's unconstitutional to try a former president.
https://www.charlestonmercury.com/single-post/a-senate-trial-of-president-would-be-unconstitutional Those arguing for the power of the Senate to try a former president bring up an 1870s case of the impeachment of Secretary of War William Belknap. This impeachment came after his resignation but set bad a bad precedent in a unique case. The constitutionality of impeachment and trial was questioned at the time and was never ruled constitutional by the Supreme Court. Importantly, Belknap resigned hours before he was going to be impeached, solely to avoid impeachment. The evidence and witnesses against Belknap were beyond dispute. Belknap had even admitted to taking substantial sums of government money illegally from the profits of Fort Sill trading posts. Regardless of the evidence, a number of House members questioned the constitutionality of this impeachment. He was impeached anyway. The Senate acquitted Belknap despite the overwhelming evidence and slam dunk case. Importantly, senators never doubted Belknap’s guilt. The reason for his acquittal was that many senators held they didn’t have the power to try the case. Before the trial started, almost half the senators voted against the trial on constitutional grounds.
https://www.charlestonmercury.com/single-post/a-senate-trial-of-president-would-be-unconstitutional Beyond the text of the Constitution, the clear purpose of impeachment remains removal from office. During the Constitutional Convention, George Mason initiated the subject of impeachment as “some mode of displacing an unfit magistrate.” The discussions were solely about removal of unfit officers and the grounds of removal. Punitive actions against the individuals were reserved for the courts after impeachment. Article I, Section 5, Clause 7 ends with the officeholder facing potential criminal and civil penalties for crimes after impeachment. As a practical matter and showing the contradiction the trial of a former president would create, the Senate must first vote for the president’s removal from office by a two-thirds vote. Only after that absurdity can a majority vote of the Senate prevent holding further public office. If that is ultimately the goal of impeachment, it must be achieved by different means.
---and perhaps the most important part of The Constitution that applies to this Pelosi/Schumer/McConnell farce--- https://www.charlestonmercury.com/single-post/a-senate-trial-of-president-would-be-unconstitutional The prohibition of a bill of attainder is critical for the protection of due process; such a bill would allow Congress and not the courts to try and convict a private citizen. Bills of attainder were used in Parliament as a way to convict individual citizens. Our founders found it absolutely contrary to due process and separation of powers. The Constitution specifically prohibits bills of attainder and therefore limits impeachment to removal of officeholders. The implicit motivation of punishing and humiliating Donald Trump after he leaves office makes clear this trial would act as a de facto bill of attainder. Trump will still be liable to the courts for any potential wrongdoing, and that’s what the Founders intended by their limitation on the reach of impeachment.
Bottom line----Can Trump be tried by The Senate after leaving office? The answer is yes, if the courts action or inaction allows them to get away with it. --However, it violates The Constitution.
I see the Times has all this “Time” on their hands to compile such subjective lists. Perhaps if they spent more time reporting the news instead of making it in order to influence public opinion in support of their agenda, they will start to regain their lost credibility over time.