The issue with my state (Texas), the reason why the state votes Republican so consistently, is specifically because of the comparative influence of Christian organizations like the Southern Baptist Convention here in this state. The higher share of "evangelical" Christians we have here renders demographic groups that in other states might be voting Democratic (such as, for example, your average suburban middle class household) more conservative-leaning here than elsewhere in the country. That's not an easy thing to overcome, especially in little towns out in the boonies like mine where the Southern Baptist Convention basically does all of the community repairs for the local government because the latter is bankrupt and can't afford to do anything anymore hardly, and also supplies much of food for those unable to afford it (and most of us can't at some point or other in any given year). When you're financially dependent on the church, it's hard to raise a voice against the good work that they do, even when they use it as leverage to introduce Bible classes in your local public school in clear-cut violation of constitutional provisions demanding freedom of religious belief.
I can't imagine an old, dying coal town like mine ever voting Democratic, or at least not for anyone the Democrats would field in today's world, because the younger, more liberal-minded people just leave. (Eventually the place will literally just die out and cease to exist.) That said, I can imagine a time in the future wherein the average suburban household might because those parts of the state in particular are becoming better educated and less religious over time. It's possible that in decades to come we will see a situation wherein Democrats will become politically viable at the state level here again for reasons like this. We already seem to be making progress in that general direction, although I find it difficult to believe that we're on the cusp of such a sea-change in the immediate future.
As to Ted Cruz specifically, I will say that the infamous Cancun vacation will definitely hurt his poll numbers...for a while. I mean I'm furious about it personally, but I'm also a rare non-Christian here and am just someone who survived the power grid failure and wants something done to prevent anything similar from ever happening again right now, immediately. The fact is that he still has an R by his name on the ballot in a one-party state though and close ties to the Christian political organizations and November of 2024 is a long time from now. *sighs* The church is the real root of our political problems here is my point. The power of institutions like the Southern Baptist Convention over our political landscape is what has to be challenged effectively in order to get us from being an apparently suicidally red state to a place of actual sanity.