If Trump is impeached, will Moscow Mitch even hold a trial?
By 
David Super lays out a plausible case that various arguable ambiguities in the Senate rules would allow Mitch McConnell to refuse to hold an impeachment trial prior to the election, and that McConnell will in fact exploit this opportunity to subvert the Constitution in yet a new way, should the occasion arise:
To hold the support of his senators, Senator McConnell may need to construct an argument asserting that he is not, in fact, violating Senate rules and precedents. Because he needs merely to make an argument that gives his senators sufficient cover not to intervene against him, I will lay out what I expect him to claim rather than assess whether this actually is the best reading of Senate rules and precedents.
The story starts well enough for the Democrats. Rule I of the Rules of Procedure and Practice in the Senate When Sitting on Impeachment Trials requires that, when House managers notify the Senate that they wish to present articles of impeachment, the Secretary of the Senate “shall immediately inform the House of Representatives that the Senate is ready to receive” those managers. Moreover, Rule III requires the Senate, at 1pm on the next business day, “to proceed to the consideration of such articles”. In addition, once an impeachment trial starts, Rule III requires the Senate to meet every day (other than Sundays) “until final judgment shall be rendered”.
Senator McConnell likely would argue, however, that “proceed[ing] to the consideration of such articles” does not mean actually beginning a trial. He will note that the rules call for the person who has been impeached to be personally served with notice of the date by which he or she must submit an answer to the articles under Rule X. (If personal service cannot be had, Rule VIII suggests that an advertisement on Fox and Friends might suffice.) The impeached person’s failure to enter an appearance does not prevent the trial from going forward: he or she is treated as having pleaded “not guilty” and is tried in abstentia.
Senator McConnell would argue that this implies that the trial would start later and that no date for the trial need be set when the Senate meets the day after receiving the articles of impeachment. He would also note that Rule XIII specifies the hour of an impeachment trial – 12 noon – but not the date.
Over the years, various statutes and Senate rules have established deadlines for the notoriously lethargic Senate to act. Some have been more effective than others. No such deadlines appear to apply directly to the holding of impeachment trials. Senator McConnell would note that at least two judicial impeachment trials were not completed during the Congress in which they were initiated. A common method of forcing business to the front of the Senate’s agenda is the privileged motion. Clever readings of the rules permitting various privileged motions might allow Democratic senators to try to bring the issue to the floor. The exceedingly complex procedural posture, however, likely would give Republican senators considerable cover to vote to sustain a point of order against such a motion.
The one person who possibly could frustrate an attempt by Senator McConnell to avoid holding an impeachment trial is Chief Justice Roberts. Article I, section 2, makes the Chief Justice the Senate’s presiding officer for impeachment trials of the president. Arguably he assumes this status as soon as the House presents articles of impeachment. If so, Rule VII instructs the Chief Justice to “direct all necessary preparations in the Senate Chamber”, which arguably includes setting a date for the trial. Similarly, Rule XVI provides that “[a]ll motions, objections, requests, or applications whether relating to the procedure of the Senate or relating immediately to the trial” would be submitted to him. Upon presenting articles of impeachment to the Senate, the House managers become parties and could present a request or application to convene the trial. I very much doubt, however, that Chief Justice Roberts would have any inclination to challenge Senator McConnell, least of all on such an overtly political matter.
Unfortunately in this particular case, existing Supreme Court precedent very strongly favors not intervening in this sort of potential internal Congressional dispute.
I think Super is right: if the House impeaches, especially if it does so just a few months before the election — which seems like the best case scenario for impeachment advocates at the moment — McConnell and the rest of the Senate Republicans will simply run out the clock, and the SCOTUS will do nothing about it.
ETA: The main reason I think McConnell will prefer no trial to a reverse show trial with a pre-ordained “exoneration” is that Trump is to put it mildly an extremely unreliable witness, who would be impossible to control. In these circumstances, saying that”the American people” should be the jury is by far the safer play. See also Murc’s point in comments that Roberts would be running the trial, not McConnell, and C.J. Balls and Strikes is all about keeping it respectable.
On a related note, I want to say something about the argument that whatever Congress does or doesn’t do now via the impeachment process “sets a precedent” for future presidents. These arguments make no sense either conceptually or practically.
The decision whether to impeach and convict is a purely political matter, no different in this regard than whether to pass a particular piece of legislation. Nobody would say that if Congress passes a bad law, this “sets a precedent” for what a future Congress should do in the future in regard to amending or repealing that law. Whether or not Trump is impeached should and more importantly will have no effect whatsoever on how the impeachment process is used in regard to future presidents.