OK, this is how the Senate can dismiss this thing without an actual trial or change its rules with a simple majority:
The Constitution does not by its express terms direct the Senate to try an impeachment. In fact, it confers on the Senate "the sole power to try,” which is a conferral of exclusive constitutional authority and not a procedural command. The Constitution couches the power to impeach in the same terms: it is the House’s “sole power.” The House may choose to impeach or not, and one can imagine an argument that the Senate is just as free, in the exercise of its own “sole power,” to decline to try any impeachment that the House elects to vote.
The current rules governing Senate practice and procedure do not pose an insurmountable problem for this maneuver.
Senate leadership can seek to have the rules “reinterpreted” at any time by the device of seeking a ruling of the chair on the question, and avoiding a formal revision of the rule that would require supermajority approval. The question presented in some form would be whether, under the relevant rules, the Senate is required to hold an impeachment “trial” fully consistent with current rules—or even any trial at all. A chair’s ruling in the affirmative would be subject to being overturned by a majority, not two-thirds, vote.
This is a replay of the argument and related procedure followed for
the “nuclear option” that changed the threshold for “cloture” of judicial nomination debates from a two-thirds to a majority vote. When the Republican leadership
floated the option in 2005, some made the case that because the Constitution conferring the Senate’s advice and consent authority does not subject that authority to any supermajority confirmation requirement, the Senate rules could not provide otherwise. Some might argue that the rules also cannot constitutionally bind the Senate to a trial of a House impeachment if, in the exercise of its “sole power” to try, it decides against one. In this way, the Senate rule may be “reinterpreted.”
The Senate has options for scuttling the impeachment process beyond a simple refusal to heed the House vote. The Constitution does not specify what constitutes a “trial,” and in a
1993 case involving a judicial impeachment, the
Supreme Court affirmed that the Senate’s “sole power” to “try” means that it is not subject to any limitations on how it could conduct a proceeding. Senate leadership could engineer an early motion to dismiss and effectively moot the current rule’s call for the president or counsel to appear before the Senate. The rules in place provide at any rate only that “the Senate shall have power to compel the attendance of witnesses”: they do not require that any other than the president be called. Moreover, the Senate could adjourn at any time, terminating the proceedings and declining to take up the House articles.
This is what happened in the trial of Andrew Johnson, in which the Senate voted on three articles and
then adjourned without holding votes on the remaining eight.