So glad you asked! My concern, as a devoted fan of the US Constitution, is the Court's reputation and function as a neutral arbiter between branches and parties. I don't want it to either be seen or act as a partisan actor. https://twitter.com/playultm8/status/1316102776905060352

But the damage has been done, and it's been done by one side. Counteracting that damage by expanding the court with (say) two more D votes will fix the immediate problem of balance but not the larger problem of partisanship. I'm more interested in lasting structural changes.

Such as, @PeteButtigieg's suggestion of a tripartite court: 5 R justices, 5 D justices, and 5 selected by the other ten. https://www.nbcnews.com/politics/2020-election/inside-pete-buttigieg-s-plan-overhaul-supreme-court-n1012491

There are other ideas, eg. staggered, limited terms so that every President gets to choose some justices, and none of them serve for life. Whatever the solution, it has to insulate the Court from politics, not re-align its politics from one side (where it is now) to the other.