I hear what you are saying. There are states that look tantalizingly close for both sides that really are not. I have heard them described as "fool's gold". Two such states that come to mind for the Democrats are Georgia and Arizona. For several cycles, both appear close. Close enough that if you dumped some money and resources, it could make a difference. Like I said both are fool's gold. The analytics just aren't there. The Cook Report actually has Arizona listed as one of 5 'toss-up' states, along with Florida, Pennsylvania, Wisconsin and Michigan. Despite that Arizona elected a democratic Senator, Arizona is not a toss up in a presidential election. Just not.
But Texas is very different than these tantalizingly close, "fools gold" type states. The numbers are moving and they are moving fast. AND the changing demographics and flipping of the majority of votes from white to non-white is only one part of a perfect storm that is occurring. A second component is Trump's igniting a fire under that electorate that normally doesn't vote in high numbers. If the trend in the mid-terms hold up, where Latinos voted at their highest numbers ever....look out.
And still there are several other problems for republicans in Texas. White Women. Trump is severely under water from his 2016 numbers with white women, but no where more than Texas. He is polling about 18-20 pts lower than the numbers that voted for him in 2016. Maybe there is some magic trick he can pull to get them back, but this group isn't easily persuadable. They seem to have made up their minds against him for now.
Another issue for Trump in Texas is the Bush factor. There is a Bush Family following, that probably won't vote for trump no matter what he does.
And finally, Texas also has a senate seat up for election in 2020. If Beto drops out of the presidential race and runs for the senate, making that a completive race, watch out. I am aware he has said he will not run for that seat. Marco Rubio did exactly the same thing in 2016 and when it came time to end his presidential race, he jumped right back into the senate race that he swore he wouldn't. I expect Beto will do like-wise.
So Texas is definitely different than other "fool's gold" states. The numbers are moving and they are moving fast and there are several other factors at play, all seemingly coming together for a perfect storm. I think Texas will flip in 2020 or come damn close. Close enough that not only will the dems dump a shitload of money, but the repubs will have to as well. They will have to spend a shitload of money defending a state that has always been a sure thing. Mark my words this tsunami is coming and it is coming quickly. And there are now a handful of republican strategists, standing on the beach, squinting out at the ocean who see it and are starting to exclaim "Oh shit!".