In California, the Registrar of Voters is the one who has the data.
Perhaps I'll do a search for it. I doubt it is internet ready, this being CA and all. Which brings us back to, can't we get this info from the Republicans and the dims? Are they not running the polls? Shouldn't they be able to provide the quantitative data to substantiate your claims?
What about getting the registered voter tally before Nov. 5 for each precinct?