The Dems contend that Trump abused, and will continue to abuse, his Presidential powers.
Trump and the Repubs say that the House abused its impeachment power.
This is deserving of discussion.
1. Separation of powers; Congressional oversight; DOJ
There is an obvious tension between, on the one hand, separation of powers of the Executive and Legislative branches, and, on the other hand, Congressional oversight of the Executive Branch that entails intrusion of the Congress into the Presidency.
No one says that the separation of powers provision of the constitution completely prohibits Congressional oversight, and, instead, everyone agrees that line drawing needs to be done between what is permissible in Congressional oversight and what is impermissible in Congressional oversight.
Where alleged Presidential wrongdoing is involved, that factor potentially affects the foregoing line drawing between permissible and impermissible Congressional oversight actions.
Further, in the context of an impeachment, the Dems argue that more expansive Congressional intrusion is permissible.
A further element in the case of alleged Presidential wrongdoing is the role of the Department of Justice, and it having independence, or not, in beginning and carrying out investigation of the President.
2. Sole power to impeach; sole power to try impeachment
The constitution states the grounds for impeachment as bribery, treason and other high crimes and misdemeanors.
There has been voluminous discussion of the grounds for impeachment.
The Trump impeachment, and its outcome, will embody one interpretation of what is impeachable made by the House of Representatives and another interpretation of what is impeachable made by the United States Senate.
These interpretations of what is impeachable will be presumably looked to for guidance in a future impeachment.
Such interpretations would not seem to be binding in the future, and a future House of Representative or a future United States Senate would ostensibly be at liberty to fashion different interpretations of what is impeachable under the constitution.
If such a future House and Senate should vote to impeach and convict on an interpretation of what is impeachable that is different from the interpretations in the Trump impeachment, it is doubtful that the Supreme Court would declare that said future Congress is bound by the interpretations of the current House or of the current Senate, and the Supreme Court would not declare that the impeachment and conviction made by such future Congress was invalid.
Based on how the constitution places the sole power to impeach in the House and the sole power to try the impeachment in the Senate, it is probably the case that the Supreme Court would not invalidate any impeachment and removal from office on the basis that the Supreme Court determined that the Congress incorrectly determined what is impeachable under the constitution, such is different from how the Supreme Court interprets what is impeachable, hold that the President has not committed an impeachable offense and invalidates such impeachment and removal.
The foregoing contention basically means that an impeachable offense is whatever the House and the Senate say is an impeachable offense.
In the abundant debate about what is impeachable, there has been little express contention that an impeachable offense is whatever the House and the Senate say is an impeachable offense. Even though there has been little express contention of the foregoing, it is doubtful that the Supreme Court would try to substitute an interpretation to restrain an alleged impermissible basis for impeachment. Rather, it is fair speculation to think the Supreme Court would say restraint must come from the House and/or the Senate, and, if those bodies arugably do not exercise proper restraint, it is up to the voters to vote out their members of Congress for failing to exercise appropriate restraint.
Impeachment is an extreme and serious remedy that a Congress should utilize with an appropriate recognition of the gravity of the matter and therefore use it with restraint. Under the foregoing analysis, it is reasonable to think that the Congress would endeavor to respect the words of the constitution and the guidance of the Founding Fathers respecting the words "treason, bribery or other high crimes and misdemeanors."
This may or may not result in acceptable restraint, and there may be great contention about what is acceptable restraint in exercising the impeachment power.
Some may contend that the impeachment of Bill Clinton was an inappropriate exercise of the impeachment power. Voters may or may not have been affected in their voting decisions in Congressional elections following the Bill Clinton impeachment.
The Trump impeachment has been contentious in the extreme, as manifested in the angry charges by the Dems that Trump has abused his power, and the angry countercharges by the GOP that the House has abused its impeachment power.
This is accompanied by the GOP argument that impeachment abrogates the fundamental democratic right and power of the people to decide who their President is.
A good argument can be made that there can be no abuse of the Congressional powers of impeachment that is subject to any restraint or remedy through the judiciary, and rather the only remedy for any such abuse of power by Congress is for the voters to vote their members of Congress out of office.
3. Due process, etc.
A further good argument can be made that the constitution doesn’t give Presidents any protections during impeachment. See
"The Constitution Doesn’t Give Presidents Any Protections During Impeachment"
This may sound extreme, but it needs to be kept in mind that the only thing that is being taken from the person who is President in an impeachment is the Presidential office, and there is no deprivation of life, liberty or property that that are sanctified with due process protection under the constitution.
This would extend to denying, in an impeachment proceeding, any right of the President to withhold witnesses and documents or to assert executive privilege.
The rationale for denying any protections to the President in an impeachment is, that as between which of Congress and the President has the ultimate authority and power to determine what is "right" and "necessary" for the nation, the Congress has that ultimate authority and power, and it is ultimately to be exercised through the impeachment power.
If that power is exercised, since the person who is President will not be deprived of life, liberty or property, but only of the Presidential office, all personal protections of due process, etc., must give way to the protection of national and public interest, all as determined by Congress.
[to be continued]
