So in 2012 I used California VoterConnect… 

So in 2012 I used California VoterConnect VAN's nifty search option which allowed you to search for "buildings with more than X number of units with voters who match the rest of the search criteria" to find all the apts in LA & OC that had more than 30 KA voters. This feature is unavailable in PDI. Nor in State Voices VAN. Which led to the manual work in the screenshot.