“Democrats paid a political cost for decades after F.D.R. tried it in the 1930s. They probably would again.” [Julian E. Zelizer, New York Times]
Some writings on the left applauding or backing the idea: Ian Samuel, Guardian; E.J. Dionne, Washington Post; Mehdi Hasan/The Intercept; Jed Shugerman; Michael Klarman, Take Care Blog. Charlie Savage at the New York Times rounds up more pro and con. And as Josh Blackman noted in April 2017, similar ideas were already floating around then; see also Mark Tushnet later last year.
Critics of the idea: Megan McArdle (recalling “Impeach Earl Warren” billboards), Charles Cooke (“fringe fantasy”), Adam White, Ilya Somin. A constitutional amendment to prevent packing? [Jim Lindgren, Ilya Somin]