I think we're headed towards a decade of D presidents once TX goes, the question is when that is. If Trump wins this year, it'll vote for the D in '24 imo. The math just isn't there for the GOP to win when the presidency with it D for the time being.
I think enough of the South/Southwest will flip to put Dems back in power for 8-12 years starting either this fall or in 2024. But by the 2030's Republicans will be able to win by just about sweeping everything north of the Ohio Rive and/or holding on in Florida.