Can Elder replace senator Feinstein?

You could have stopped right there.

Fortunately, this option is obviated, at least for now.

I was pleased with the results and the margin, the turnout (about 10.1 million out of 22 million or so eligible, or about 46%) was reported as large, and it probably is for a weird off-year election, so I guess I’ll have to be satisfied with that.

I would say the answer to the title is, no.