long tail/tale of impeachment a look at intellectual dishonesty
blowback or demise of democracy
Founding Fathers had it covered

Some brilliant people, with centuries of monarchial oppression to work from, wrote the United States Constitution.

That document set the stage of the rights of each citizen and the rules under which the Legislative (House/Senate), Executive (President) and Judicial branches must operate.

By way of that Constitution, "We the People" also set up a brilliantly simple, even childish system of checks and balances (think rock, paper, scissors, lizard, spock).

Every two years the People control the House, every six years the Senate and  every four years the President.

The people even control the Constitution they wrote.

The House and Senate, Congress, if it really wants to, controls the President at any moment with regards to laws (legislation) and Presidential malfeasance (impeachment).

The House and Senate work together to create laws for Presidential review.  If the President rejects (vetoes) a House/Senate passed proposed law, the House/Senate can override the veto with a 66% vote.

Thus, the ultimate power of law in this country belongs to first the People, then a body, the House and Senate, or Congress, and not an individual.

By that same Constitution, House is given the sole power to signal, by way of impeachment, if they think they see the smoke of Presidential malfeasance, so long as the body thinks there is smoke at > 50%.

Also by way of the Constitution, the Senate, being informed by the House of the perceived smoke of malfeasance, is given the sole power to remove the President if the body finds that there is substantial fire where the House found smoke so long as 66% of its members think so. 

In addition, that now removed President can thereafter be prevented from holding any elected office by a 51% vote by the Senate.

So, in the end, the House and Senate, the Congress, has ultimate immediate authority over the Executive regarding malfeasance and the people every 4 years.

It is a nice cross of a large mass able to react quickly (there's smoke), the House, and a more staid, longer term institution (is there any fire that needs to be put out), the Senate, can triangulate on the actions and capabilities of the President, and, if those bodies fail to act, the People. 

All quite elegant work by he founders.

Impeachment = Indictment?

The constitution gives the House, a non-judicial body, the sole power to  impeach the president.

From appearances, impeachment has all the trappings of an indictment, an accusatory instrument by a public body empowered by the Constitution.

For the little people, if a case is presented to a public body, a grand jury, all that is necessary for the potential defendant to be charged, is the appearance of the likelihood that a crime has been committed.

It is extremely rare for anyone under investigation to even be informed of the grand jury presentation, let alone present evidence or a defense.

When the U.S. Constitution gave the sole power to impeach to the House, it is hard to see any other reasonable interpretation than to it being equivalent to an indictment.

Try = Trial?

The Constitution gives the Senate the sole power to try an impeachment (indictment) of the President.

The only requirements, beyond each senator taking an oath to  "" and the SCOTUS judge breaking ties,  are that the senators can remove the President with a 2/3rds vote, and,  then, prevent the President from ever again holding office with a majority vote.

The oath:

I solemnly swear (or affirm) that in all things appertaining to the trial of ____, now pending, I will do impartial justice according to the Constitution and laws, so help me God.

The operative word is try, an open ended term, as the constitution does not say trial.

Nowhere in the Constitution is the term try defined, but the oath says the "try" must be according to the Constitution and laws.

It seems obvious that, so long as the process is fair, the Senate can vote with its heart, gut and mind so long as it follows the Constitution and laws.

The open question, is what laws?