Paul Mitchell has some excellent advice for campaigns coming to California for the June 7 primary. As Tom Petty famously once sang, "It ain't like anywhere else." Too often both the NRCC and DCCC think you can plan and manage a California campaign from Washington. We have a word for those campaigns. Losers. When we do campaigns here we use data. As Paul says, we have a lot of it. We laugh at pollsters who include people in their poll because "if they say they're voting and they complete the poll they're surely voting."
No, they're not. When the Presidential campaigns get here, they'll hire political consultants. Maybe they already have. If those political consultants aren't telling you that you should only target 4s and 5s, then you should fire them. What are 4s and 5s? I'm assuming candidates aren't asking that question, because their smart political consultants have informed them what they are. For the rest of you, California provides data on how many of the last 5 primary and general elections a voter has participated in. Primary turnout in California is fairly low. A campaign knows that it can count on people who've voted in 4 of the last 5 or all of the last 5 elections turning out for the primary. Voters who've turned out in 2 or 3 of 5 mostly won't show up in the primary, let alone voters who've turned out for only 1. You're going to waste a lot of man hours trying to get those voters who've shown up for 1-3 of the last 5 elections to show up for a primary. The most efficient thing is to put your resources to the people you know will show up.
What about those people who've shown up 0 of the last 5? Purging California rolls of people who've moved or passed away is handled on a county level. Some counties attempt to purge, while others don't bother. Orange County registration went down by 15% from 2012 to 2016, while Los Angeles county registration went up by 2%. This isn't because people moved away from Orange County and not from Los Angeles county. It's because Orange County did a voter roll purge, while Los Angeles didn't do one. So Los Angeles County probably has at least 15-20% non-voters on the rolls. If someone hasn't voted it's a decent bet they no longer exist at that address. So those phantom voters are definitely a big waste of time.