Although I am cross-posting much of this from another thread, a practice I hate, there is substance here that needs to be reiterated:
An impeachment is not an indictment, although it has some equivalence, but it is more than that. It is a deliberated determination by a body of Congress. It is its own thing. Trump is Impeached. It is a done thing. The House
has spoken. It cannot, as Rep. McCarthy has claimed, be "undone". The next stage of the process is to transmit the articles of impeachment to the Senate for trial. That is a
procedural, not a substantive, step. It does not affect the reality of
impeachment.
The Senate, as a separate body of Congress, has a separate responsibility. The Senate conducts a "trial". Although undefined, a trial in American jurisprudence has a meaning, an implication, and expectations. The Chief Justice presides. It requires some kind of "due process", although it is not, a
nd explicitly so, a criminal proceeding, and does not import criminal conceptions like "proof beyond a reasonable doubt", "innocent until proven guilty", "cruel and unusual punishments" or a unanimous verdict. To make these arguments is to misapprehend its purpose. The Senate trial is an administrative or "civil" proceeding. Rules of court do not apply - evidence, procedure, etc. The Senate creates the process and establishes its own rules. Some things are expected: Presentation of evidence, opportunity to rebut, arguments. Beyond that, the "trial" is whatever the Senate wants it to be, subject to whatever the presiding Chief Justice might interject.
Moreover, the Senate is extremely limited in its responses. It cannot "unimpeach" the President. It cannot "exonerate" him. It can only "convict" or "not convict" an impeached officer. Upon conviction it can: do nothing, remove him from office, bar him from future office (by a simple majority vote). (By tradition and implication it can impose a lesser punishment, such as
censure or reprimand, but that is technically separate from impeachment.) It cannot jail him, banish him or take other punitive actions. In impeachment proceedings the "defendant/respondent" does not risk forfeiture of life, liberty, or property. Indeed, the Constitution so states:
The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two-thirds of the Members present. Judgment in Cases of Impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States
Although, "the Party convicted shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law", that is a separate process.
Sure, the Senate majority can "short-circuit" the trial process, but it will be out in the open and offend about 70% of the population who would see that as "unfair". Many of those people would probably vote. So, there is that.
There is a third option that the Senate could consider: They could convict, and merely bar Trump from
future office. It is a constitutionally tricky proposition, but might be a compromise for some Senators.