RBG knew she was sick, but she wanted to do a little more work. Understandable and not unusual. She even found some popularity with the younger generations. I figure that when the next election cycle came around, she was thinking that Clinton had it in the bag. She could then retire, and her seat would be filled with a similarly minded individual.
Then Trump wins
I believe that at this time, RBG then decided that she was going to stay and stick it out and hope for the best. It didn't work out. She died with Trump in office and a Senate who is of the same party. Her seat will be filled with by a Republican President.
~Jeordam
Saving the Princess, Humanity, or the World-Entire since 1985