Registration may be cancelled for specific causes such as death, imprisonment for a felony, a finding of mental incompetence, etc. (EC 2201.) These are very specific and require proof and would be difficult or impossible to misuse.
The Elections Official must check for invalid addresses before the primary election. (It is not clear whether this applies to the Presidential primary or general primary). This may be done by mailing a residency confirmation postcard to each registered voter. The text on the residency confirmation postcard is specified in EC 2220, so returns of general informational mailings may not be used to initiate the process.
The Elections Official may instead use Post Office Change of Address data or check for returns of sample ballots if there was an election in the preceding six months.
If the postcard was undeliverable or the Post Office indicates the voter moved, there are a number of procedures to follow depending on whether the voter has no change of address, has a change of address within the county, to has a change of address to another county. The most severe consequence would be for the voter's registration to be moved from the active voter file to the inactive voter file. This does not appear to have any affect on the voter if he or she wants to vote. Rather, it means that sample ballots will not be mailed to the voter and the registration will not count for statistical purposes. If the voter does not vote in the next two federal general elections, the voter's registration would be cancelled.
This summary was prepared by a non-lawyer; use at your own risk. Consult the California Elections Code, Division 2, Chapter 3 for more information.
Nov. 1, 2007: jb