There were so many changes to politics in the 1980s that trying to connect the Chevron ruling to the decrease in bipartisanship, which was already decreasing as the political parties transitioned into opposing alignments, is a serious stretch IMO. The 1980s, starting with the election of Reagan, were when the Conservative party realigned itself entirely in opposition to the Liberals of the time.
It is hard to imagine now, but political scientists in the 50s and 60s were arguing we needed more ideologically pure parties because the parties were so intermingled with each other.
My pet opinion is that in the late 1960s to early 1970s the United States, for all intents and purposes, became a post-scarcity society. This means that politicians stopped trying to figure out how to make the pie big enough for everyone, which they could find some middle ground arguments for, to how the pie should be distributed. The latter is not a solvable problem, just an endless argument, so here we are.
It is hard to imagine now, but political scientists in the 50s and 60s were arguing we needed more ideologically pure parties because the parties were so intermingled with each other.
My pet opinion is that in the late 1960s to early 1970s the United States, for all intents and purposes, became a post-scarcity society. This means that politicians stopped trying to figure out how to make the pie big enough for everyone, which they could find some middle ground arguments for, to how the pie should be distributed. The latter is not a solvable problem, just an endless argument, so here we are.