Sorry but you lost me on your discussion of the democrats shoring up California, and the republicans Texas.
Getting back to the first point ~ why political campaign managers watch polls ~ if the polls are no good they'd be stupid to do what they usually do when polls change.
The Dems will get Maryland and California no matter what the polls show ~ and that's mostly because the polls are useless. No sense at all Republicans spending a lot of money in either place ~ just be a waste of money.
HIstory is my guide on those two places.