Gerrymandering has been a tradition of the Democratic party since their opponents were the Federalists. Republicans have picked up on it as well (annoying the Democrats who thought they had patented the idea, and didn’t want to share). The only restriction is gerrymandering in order to keep Blacks (or at least, those Blacks whose ancestors were slaves in the antebellum period of American history) from getting elected. The alternative system would involve proportional representation (such as in Israel), which you never have your “own” legislator, and individual legislators ignore voters since staying in office is totally dependent on winning favor from party leaders (who write up the lists).