Many do. But as the last election showed, Texas is much closer to being flipped than people realize. You don't need even the vast majority of these communities to flip. Flipping some and a few more simply refusing to turn out would close the gap.
To truly ameliorate things in the United States, its not a simple matter of ousting the GOP for one election cycle or even three.
The Democrats, typically, have more appealing policy ideas to Canadian ears; but rarely implement any when they have full control of Congress.
As an example, Obama's first term, the Dems had full control of both houses of Congress and didn't pass a minimum wage hike, not even .5c ; even though it was in Obama's platform.
There's a level of money in our politics here that is or should be very troubling, but it is that much worse south of the border.
There is a need to get structural fixes to their election process; ranging from ditching gerrymandering, to imposing tough campaign spending limits, to ditching the electoral college, amongst others.
There is a need to address media concentration, where there the decision of one just one or two players to not accept candidate ads or to otherwise de-platform or under cover them completely shifts the field of candidates who can contend for office.
I'm not sure I much hope of any of those things improving or being tackled in the near or even medium terms.
Perhaps a sweep by Dem's will improve the rhetoric some, or allow for a belated minimum wage hike or some modest expansion of health insurance......... better than swift kick to the head. But hardly sufficiently ambitious to tackle the problems that country faces.