Impeachment of the president is a certainty. It became a certainty the day Nancy Pelosi became Speaker of the House.We ought to suspect that the Democrats have done extensive lawfare wargaming to see how a variety of alternative impeachment strategies might play out. These strategies are likely being updated as needed depending on the course of events.
If it is in fact possible to change the Senate rules by a majority vote, it is easy to suspect that Romney, Murkowsky, and Collins might side with the Democrats and vote those changes to the rules needed to empanel a smaller jury of Senators for the trial.For example, if the jury consists of twelve Senators, then eight votes out of the twelve are required for conviction, not 67 as is the case if it is the full Senate acting as the jury.