If you wondering why dems are freaking out about Texas entering the gerrymandering business, this should help explain things. They don’t have the avenues to offset it because blue states with the necessary majorities are all already gerrymandered straight to hell. Though you wouldn’t know it if you looked up “democrats gerrymandering” since that’s only a word aimed at republicans even though democrats are the worst offenders. Which is why republicans have options to give themselves seats in several states but democrats are maxed out.
Mass is a deep blue state, but not so deep blue that they should not have even one lean red district. They aren’t the only ones.