First off, there's no such thing as a Red State or a Blue State. That's just nonsense. That's why King Blue, New York, is not even on your list.
And while gerrymandering is something that's has been pushed by both major parties in states, the ones who do it the most are by far are Republicans and this is been known for decades. If it wasn't for gerrymandering, Republicans would be winning as many seats as they have been winning presidencies by popular vote for decades now.