But the stakes were not frivolous in the 1990s, when justices were confirmed by cross-party landslides.
Both Ginsburg and Breyer were being considered in a 56-44 D Senate. The Republicans had just flipped Marshall into Thomas, so White into Ginsburg was maintaining the split (since Bush had also appointed Souter) and Blackmun into Breyer wasn't changing it.
The Kavanaugh appointment is more similar to what put Kennedy on the court in the first place. Powell to Bork was a shift heavily to "the right" and so got shot down. Kennedy passed 97-0 because he was a swing vote, arguably a superior one to Powell. Kavanaugh shifts the swing vote to Roberts or Gorsuch, which isn't much of a swing vote and thus doesn't maintain the status quo.
The Republicans didn't even want to take a chance on any of their "moderates" voting for Garland in because it was Scalia's seat. Even Democrats were less concerned about putting Gorsuch into that seat, despite everything that happened over it, because it maintained the status quo. Had it been for Ginsburg's seat the GOP probably wouldn't have denied the nomination completely and let it come to a floor vote since it wasn't changing the status quo.
Democrats let Roberts into the Chief Justice seat without much of a fuss because he was arguably better than Rehnquist anyway. But he would have had a closer vote, like Alito did, had he been replacing O'Connor as he originally was supposed to.
At risk is the legitimacy of the Supreme Court, a nominally extra-political sanctum that is increasingly fought over as though it were the third legislature.
But this was just a always silly myth. The Court was the body that did what Congress never could bring itself to, and declared blacks to not even be citizens, overturned the Missouri Compromise and the incoming President was lobbying Justices to join Taney's decision so it didn't look like only a Southern thing and so the issue would be "settled" when he took office.
Abe Fortas wasn't unusual in a Justice being an adviser/spy for the President.
The Court (and thus, the courts writ large) has been
openly tasked to "settle" more and more political questions because they're the only body that doesn't have to answer for its actions in some way. Well, them and THE DEEP STATE.