I agree with all that, but even the pollsters argue that the swings in the national polls are due to changes in the swings states ... they track together.
Yes, Texas getting more red is no more or less valuable than NY getting more blue.
I remember, e.g., when I was voting for Mr Mondale, and that at the time the relevant battles for me were in the Senate. In that year Al Gore and Tom Harkin flipped some seats to the democrats whhile the very yucky Mitch McConnell surfaced.
These broader numbers will dictate the circumstance of Warren v Brown and such.
the narrative decribed by debate #1 will not flip MA, but Warren Brown? McCaskill/Akin? etc?
I suspect that a more runaway narrative will be required to carry some or many seats in the broader context of the house and senate ... in other words, that 3 points or 6 points in Texas DOES matter ... but only down-ticket and what might happen in the suburbs of San Antonio e.g.
But down-ticket matters.