Given the present focus on police brutality, defendant rights, and mass incarceration, the Garland pick is definitely controversial among progressives, but (1) he’s still going to swing the court to the left especially since he’s replacing Scalia and (2) it’s unlikely that Senate will confirm him anyway.
People talk about “order” and “stability” as if they’re one and the same, but order isn’t stable. Order always requires energy to maintain. It’s the state of maximum entropy that’s stable.