I selected "open primary" even though this is just a P&F primary because there was no other option other than the two major parties.
A rare third-party primary!
Source for Popular Vote data: California Secretary of State. Statement of Vote 1998 Primary Election June 2, 1998, California Secretary of State (http://primary98.ss.ca.gov/Final/P98_SOV.pdf) (accessed 12 Feb 2007)