Things aren't quite as polarised now as we sometimes like to think.
It's the difference between political hacks (very polarised) and normal people (still happy to ticket split)
Except that in some states like CA, the number of hacks and trolls very much outweigh the numbers of normal people.
Compare the election results of San Bernadino and Riverside counties in 2000/2004 vs. any of the Bay Area counties in the same two elections. In the first two, there is a marked change; in the latter, hardly any change.
The bay area had a significant pro-Democratic swing.
