Only up to a tipping point. If the election were held today, a 50-43 pv for Mittens translates into an electoral landslide without regard to state-by-state polling -- the red states simply don't have enough voters to electorally account for such a robust defeat of Bobo ie Mittens would pick up many Blue states if that many Dogs sat on their hands at 43.
Not unironically, something like the 50-41 Reagan-Carter pv, albeit electorally it would be a bit closer than that 489-49 EV thrashing. More like 360-178, which is probably Mitten's limit, picking up outlier states like Maine, etc.
Now, you get a tight pop vote race, like 48-47 (Gore-Bush), different story. Absolutely state-by-state polling is the key in that instance.
“Only up to a tipping point. If the election were held today, a 50-43 pv for Mittens translates into an electoral landslide without regard to state-by-state polling -”
I agree, but I still like to see those state poll internals as state polls seem to be less influenced by daily fluctuations. They usually are taken on a set schedule and not done on a daily tracking.
I like to watch the trends within each swing state and see how each state is trending. I think that is a more solid basis in predicting where the swing electorate is.