Had fair maps been in place in Ohio and Utah, as well as additional Black-performing seats in place in Alabama, Florida, Georgia and Louisiana, Democrats may very well have retained control of the House.
https://www.democracydocket.com/analysis/how-gerrymandering-helped-republicans-win-the-house/
https://www.democracydocket.com/analysis/how-gerrymandering-helped-republicans-win-the-house/