When you boil Trump (& the consequent Trumpism) down to its essentials at root it is Lying.
Trump has made a life of being a liar.
It is "Trump Rule#1" expressed years ago "Trump is a liar. He does not simply tell lies, he IS a liar. Thus what he does is quintessentially a lie".

Now we are embroiled in an impeachment trial, the consequence of the ultimate Donald Trump lie.
That he won the election.

This is so fundamental a lie, that when pressed, as Trump has done, & married to a demagoguery, as he had utilized to enflame his believers, you get

what we got. A mob. Playing at an insurrection.

All because of a Lie. Propounded by a liar.

Here then is the first brick in the edifice that is the newly submerged & subjugated Republican Party:

Renounce the Founding Lie.

If they will not, then nothing else matters.

The impeachment trial itself is become a farce, not for the lack of an impenetrable prosecution case.
But by the dint and opportunity allowed the structure of the impeachment process, to avoid all and any facts by the simple tactic of embracing, and advancing, a lie.

The Republicans as a Party have subordinated themselves to a Lie.
The Republicans as a Party have accepted as their functional premise for governance and leadership a Liar.

Until these cornerstones of what unifies the Republicans, devoted to their party, and not the country,