Only 3 Republicans understand policy disagremeents are not grounds for impeachment of a cabninet officer?
The idea is that impeachment is for high crimes and misdameanors,
But in practice it's simply a way the House and the Senate can remove an elected official from office, simply by voting (>50% in the House AND >66% in the Senate).
Typically a person exposed for doing crimes would remove themselves from office(for the integrity of the House, the Senate, the party). A person without integrity, without concern for the institutions or party will not (especially if they have a lot of influence over party members.
So when they won't quit, this provision is here so that other members have the opportunity to kick these people out.
But there is no check and balance to ensure that the House and the Senate do what they are supposed to do. They can decide not to impeach and not to convict someone who has been proven guilty of crimes, and they can decide to impeach and convict someone that has not been proven guilty of crimes. It is up to them how they want to vote.
The ultimate power is with the people. The people can decide to enforce integrity into the House and Senate by taking note of who votes to impeach or not, who votes to convict or not. The people can clean up the corruption in government by not voting for corrupt government members next time the votes happen. If the people did vote out House and Senate members for not following the evidence and upholding the integrity of office, then this would send a clear message to members, the next time an impeachment hearing happens, to take the process seriously.
HOWEVER, in an environment where the people don't care about upholding the law or the integrity of the office, then impeachment is for something entirely different (not for high crimes and misdemeanors).
Instead, impeachment could be for disloyalty to D Trump. If D Trump wants someone impeached and convicted then members of D Trump's party are expected to vote that way (regardless of evidence or crimes). If they don't vote that way, then the Republican supporters will vote THEM out of office when the time comes.
It seems, to me that in today's environment the Democratic Party members mostly use impeachment for high crimes and misdemeanors and the Republic Party members mostly use if for loyalty to D Trump. And this is supported by most of the Democratic party supporters who want impeachment to be about high crimes and misdemeanors and most of the Republican party supporters who want impeachment to be about loyalty to D Trump.