What you’re talking about is exemplified by Bush v Gore, when the Supreme Court decided the election it was Gore that happily conceded because he and Bush were just having a friendly competition. That was before the empire began its decline, what used to be collaboration between friendly rivals is turning into infighting. The partisanship we see is actually a side effect of deeper troubles.
Fundamentally disagree. The political theater is not showing a deep divide between agents. It is reflecting the deep divide between voters.
That’s certainly still true to a degree, but the way the US’s political system is set up means that the True Believers of the theater bullshit are now the ones getting elected. They get elected to city, county, and state level offices as well as the federal House. It hasn’t gotten to the point where the brain rot has reached the Senate (yet), but every level below that is filled with up-and-comers who really believe the partisanship is real. The old guard of the empire is all in their 80s and dying off, these younger politicians are completely disconnected from realpolitik because they grew up in the neoliberal End of History. That’s why we have shit like Texas having a showdown with the feds over the border lol
Transmission of empire happens in universities, in big business, and in the halls of power. The new guard has gone through that process just like their predecessors. That their behavior is more erratic, again, speaks to the psychology of the voters more than the psychology of the officials.