Texas only trended a point left in 2020 and has average education attainment. I don't think Texas will continue be 10 points to the right of the nation, but I doubt it will soon become the tipping point state.
The hope for the GOP is that gains among urban non-White voters match the losses with educated White suburbanites in Dallas, Tarrant, Harris, and Bexar. The Austin metro and Collin/Denton will definitely trend left but they aren't that much of the state. The TX GOP will also hope that the RGV flips, El Paso gets close, etc.
Many of the gains the Dems have gotten aren't because of nationwide political trends exactly. The GOP was performing unsustainably well among TX educated suburbanites prior to 2016, so any investment in TX from Dems would yield huge swings. The same is the case in metro Atlanta. More broadly, one big factor in any 2012-2020 swing was the evaporation of most local advantages. Now that TX has been in play for a few cycles those gains might become limited.
This^
A lot of the "Blue Texas" spreadsheet math on ET assumes that the 2016-2018 shifts were actual trends in those years, and extrapolated from them, rather than a reversion to how Texas should have been demographically voting since 1996.
Based on educational attainment, racial and economic demographics, Democrats should have been performing substantially better than they did 2000-2014, and it is less that Texas was more Democratic in 2022, than that Obama/Sadler/Noriega should have done much better in 2008/2012 and 2006 was nothing short of an embarrassment.
If Texas was a 53-46 state voting 58-41, then getting to 53-46 is less a result of Democratic growth per se, and more the Texas GOP losing its unique brand versus the national party. Which makes sense because George W Bush/Rick Perry/David Dewhurst have been replaced until John Cornyn and to a lesser extend Abbott himself are "moderates".
Exit polls don't really support the idea that an influx of out of state migrants is what is turning the suburbs and exurbs bluer. Unlike in Georgia, they show in-state migration is if anything Republican.
A wider issue in Texas is the "brand" of the two parties. The GOP had a uniquely strong brand which has been tarnished over the last decade but the Texas Democrats have not really made much progress in producing a Texas brand. Their leading figures do not represent the places they have made gains in for the most part, with the result that , like liberal Afrikaners under Apartheid in South Africa, the few they have are pushed to run statewide too early(Wendy Davis, Beto, now Allred) and burned up.
Associating the Democratic party with the ascendancy of the Atlanta suburbs worked in Georgia. The fragmented nature of Texas means the party has to chose between Houston and Austin, Dallas and the border. Heck, they even have to chose whether they are the party of Dallas or Fort Worth, much less Collin.
What aids them is that Republicans have a similar problem. But it's nowhere near as bad.
But for those who expect a Blue Texas, what does that even look like? Who would be the type of people who would be elected?
That's what I struggle to visualize. Not extending lines exponentially. That part is easy