This has happened in the United States as polarization based on differences over issues has morphed into something much more dangerous, what the scholars call affective polarization where each political party comes to see the other as a fundamental threat to the democratic order and to the principles they hold dear. Under those circumstances, compromise becomes a form of betrayal, and compromise is one of the major practical expressions of this idea of forbearance.
This argument or this discussion of norms is embedded in a much more serious historical development in the United States and elsewhere; namely, the polarization of the major parties, the disappearance of the centre, the increased difficulty of reaching compromises and honourable agreements on just about anything, so everything becomes a matter of partisan warfare where no quarter is given. This is not the formula for a healthy democracy.