First of all, there are many types of Gerrymandering, even racial Gerrymandering.
Second, the idea that no Gerrymandering happens in Senate races is nonsense.
U.S. senators and presidential electors are elected at large from States, U.S. representatives from congressional districts of about equal size. Within States, representatives are elected to legislatures from a structure of districts totally unrelated to the federal senate and congressional districts.
@RememberUsAlways senators are elected by regions that don't have the option of being manipulated between elections. To say that there is gerrymandering in the Senate is to use a definition of gerrymandering so expansive that it loses all meaning.
If all elections are gerrymandered, then there's really no meaning to the word anymore. It no longer represents manipulation for the sake of power, it becomes just, you know, voting.
So no, for any practical definition of the word, there is no gerrymandering in the Senate.
So the theory that this is caused by gerrymandering is scientifically rejected by the outcome from the body that has no gerrymandering.
It makes for a dramatic story, but it just doesn't match reality. And it makes it easier to point fingers at Boogeyman instead of facing the reality that the unwashed masses around us have to be convinced over to your personal preferences if you want to make progress.
It does no good to cling to those conspiracy theories, Even if they support a simpler world.