You don’t have the UC admission policy correct.
Local option — the class rank guarantee — means only a seat in the UC SYSTEM, and, effectively, only gets one a seat in the least-competitve UC campuses (Santa Cruz, Santa Barbara Riverside and Merced). Virtually no local option students are admitted at Berkeley or UCLA, and few at the middle tier (Davis, San Diego and Irvine).
The top UCs still practice affirmative action, of course, but in a watered-down “obstacles overcome” system. While still biased against whites and Asians, this system at least avoids the worst excess of affirmative action: admitting as “underrepresented” the children of already successful and well-educated parents. (Stanford, of course, will still give more points to Colin Powell’s kids than to those of a melanin-challenged Wal-Mart checker.)
That 5% affirmative action set aside caused many well qualified students to be turned away to make space. Many of those turned away were Asians with great GPA and SAT scores. It was a total travesty.