You are actually hanging your hat on Ann Richards, the broad who got in only because of the tongue of Bill Clements and was unable to win reelection?
BTW, that was 28 years ago she was elected Governor. Guess how many Democrats have been elected statewide since that time? And we have been 'deeply independent' the whole entire time, so that 'heartbeat dynamic' has been thumping otherwise for a long, long time.
And I do not know what Willie Nelson has to do with it. Was he elected to some office or are you just sorta hoping he would?
It isn't that long ago in people's minds. I know many people in Texas who by all account, are died in the wool Conservatives, but would never vote Republican or may have under Bush. But, they would change in a moment if the winds blow differently. I can walk down the street now and find 10 senior citizen neighbors who used to be Yellow Dog Democrats, who voted Republican for a decade, but would switch in a heart-beat if they don't like the candidate. Some aren't into the labels game as we think isolated in political forums. They will vote for who is familiar and seems likable.
As for Willie, well don't discount what pop culture attractiveness can do. He is one example, but our favorite native son. If Willie started making commercials with Beto, even if it changed 1-2% if it doesn't sound like much, it could change the dynamic.
Either way, always, always fight like you are 20 points down. Don't take anything for granted.