Theoretically, what would stop a future Congress that was heavily dominated by one party from impeaching all congressional members of the opposing party and assuming 100% control forevermore? That would also extend to the White House if they were to simply impeach the opposing parties Presidential candidate, say a month before the election (assuming that person had ever held Federal office in the past).
It is part of coordinated effort. The democrats believe that if they can pack the supreme court, add states that are exceedingly likely to vote for them, and remove those who oppose them now, then they can hold power perpetually and crush all opposition. That is an exceedingly dangerous game, and there are two chief threats to it (and by extension all Americans).
First, and less likely, is the risk that geographically concentrated and politically disenfranchised people band together and leave, otherwise known as secession. A political system can tolerate dispersed politically disenfranchised people and it can tolerate geographically concentrated people who still feel that they are represented as the "loyal opposition", but not the combination of disenfranchisement and concentration. A serious effort to change the rules of the game to one side's advantage based upon razor thin political majorities could easily be a spark that ignites a fire. Note that people underestimate this risk due to the precedent of the Civil War, which isn't a good analogy. The divide now is urban vs. rural, which implies a very different geographic boundary. No state is likely to secede, but perhaps 70-80% of counties might. I believe that we are fortunate to have enough sane people left in congress that these measures will fail. Further, I believe that issue number 2 will rapidly overtake these considerations.
I make no secret of my belief that the American and more broadly world economies have been on very poor footing since 2000, more acutely since 2008, and immediately since 2018. The decline of working people in the form of lower relative wages in the face of massive wealth accumulation by the top 1% is the major driver that leads to political results (i.e. there are people who will vote R or D no matter what, but the true undecided voters just want help). We have pushed our bastardized version of Keynesian economics (instead of save in good times and spend in bad times, the government just borrows and spends no matter what) to its breaking point. We have leaned heavily upon the world reserve status of the dollar while neglecting the factors that provided and maintained that windfall. Meanwhile the unrestrained printing of money has favored the stock market at the expense of everyone who is not heavily invested in it. We are now so desperate to maintain the facade that we have resorted to massive, ongoing Federal Reserve purchases of risky loan assets and helicopter money. We have pushed the economy into a deeply unstable position in which a stagflationary recession is essentially unavoidable; recall that Volker's solution to that problem in 1980-1983 was an FFR between 10 and 17%. How will the stock market or even the underlying companies comprising it fare if a 30 year Treasury carries 18.5% or a 15 year home mortgage yields 20%?
I was deeply worried when Trump was elected because his decision to continue the economic policies of Clinton, Bush II and Obama made another crash on his watch almost certain. He pushed the printing press to the limit, and combined with the corporate tax cut, managed to push that evil off for 4 years. Had the crash occurred while he was in office, I believe that the fallout would've included a massive wave of socialist fervor in the US that would've changed the fabric of our nation and economy irreparably. As it stands, that wave will crash on the Democrats, not for them. If the GOP has any political intelligence (I am not convinced that they do), they will seize upon the profound economic hardship, lay the blame squarely upon the Democrats, and win control of the House and Senate in 2022. The would then be in excellent position in 2024, running against a senile old guy whose campaign slogan was "Not Trump" or a VP who garnered exactly zero votes in her own party's primary.
As a libertarian, I view one party rule as dangerous regardless of which party is in control, and the self-reinforcing oscillation of "You did this to us the last time that you held power, so we'll swat you down even harder now that we've got the chance" is ultimately self-destructive. I believe that the only cure is for people to speak earnestly with one another about what they actually want from government in very general terms, rather than parroting policy positions or defending politicians (most of whom wind up being pretty slimy). There are plenty of crazy people shouting insane things in the political sphere, but there are far more people who just want a good job, healthcare and education. Most people who are anti-gun hold that view because they have seen guns as portrayed by Hollywood (people being shot) and the news (people being shot), which would grossly distort ANYONE's view if not countered by other information (i.e. seeing how firearms are actually used).
These impeachment proceedings drive us closer to the terrible outcomes outlined above, and are dangerous to America regardless of one's political leanings or thoughts on Mr. Donald J. Trump. I will continue to pray for our nation.