Checks & balances. That's why we don't want a 1 party government.
Trump certainly was not a seasoned politician and acted more like a sneaky/demanding CEO and even a spoiled brat at times, but could never get away with bending the rules like he could at a private company.
Stacking the court, nuclear option, removing the filibuster, frequent and misuse of reconciliation, allowing felons & illegal immigrants to vote, and preventing states from enacting voter ID requirements are much more threatening to the integrity of our democratic republic than anything Trump did, in my opinion. These Democrat proposals purpose to remove the competing party so there can only be 1, them.