Should the Supreme Court be reformed to include more seats and term limits on judges?

In early 2020, several Democratic presidential candidates including Kamala Harris, Elizabeth Warren, Kirsten Gillibrand, Pete Buttigieg and Beto O’Rourke offered different proposals to reforming the Supreme Court. The proposals include adding 5 democratically elected judges to the current court and imposing term limits on current judges. According to the U.S. federal statute, justices have lifetime tenure unless they resign, retire, or are removed from office. Proponents of Supreme Court reform argue that the current court will be filled with too many conservative judges for the next several decades and it is not representative of the US population. Opponents argue that the plans are unconstitutional, would upset the balance of power and reinforce the idea that there are Democratic judges and Republican judges.