Since 1900 we have had 7 Democratic Presidents.
Guess how many of their "successors" won the presidency with an Election? The answer is 2, Truman and LBJ. Guess what Truman and LBJ have in common? Their predecessor president died in office.
What was RBG thinking in 2013 and 2014? In those years Obama surrogates in the WH administration were asking her have you "considered" retiring while we still have the Senate with 54 votes. RBG was 80 and 81 at the time.
RBG literally believing in her own invincibility and her "legacy" to shape the court. There was a Emily Bazelon piece in the last 24 hours about why RBG justified her decision. (Emily is research fellow at Yale Law / she is a lawyer, but she also writes for the NYT magazine and Slate)
https://www.nytimes.com/2020/09/21/magazine/ginsburg-successor-obama.html
I find all of the arguments unpersuasive now but also years ago.
Sidenote I forget about the 2009 RBG comments about Abortion in an interview Emily Bazelon did for this, and how there were controversy of no follow up question of something that RBG said that sounded malthusian / population-bomb / eugenics-ee.