I live in Berkeley and have tried to puzzle out this particular issue a bit. Here are some things I've learned:

* The title is misleading. Science labs will still be offered at BHS only they will take up more hours of regular class room time (they same way they do in every other high school in California). What is slated to be cut here are science labs during "extra periods" outside of the usual schedule. Overall, this would mean less hours for teaching science (labs and classroom) but the hours available are still in line with what is available at other, fine performing California high schools.

* BHS has the highest "achievement gap" in the state, along racial and economic class lines. Roughly speaking, the Hispanic kids perform (on average) at about the achievement level goals. The White and Asian kids (on average) above the goals. African American kids and poor kids (on average) fall below the goals. This is the basic inequity that the principal is attempting to address.

* The racial and class divides at BHS mirror the city as a whole. Berkeley is comprised of extremes: quite a few quite poor and quite a few quite rich people. Many people probably think of themselves as being in "the middle" of that but, really, it's a very polarized economy. The economic class divide coincides heavily with racial lines (e.g., odds are a poor person is Black and a rich person White). The high achieving kids tend to be, well, very high achieving: lots of AP classes and other fancy attachments to their HS diploma. They tend to be college bound. A lot of them come from rich families. This is one source of the polarized politics around the proposed changes at BHS.

* Faculty at BHS are antagonistically factionalized. BHS is divided into semi-autonomous "sub-schools" (called "small schools"). Students opt-in to one of these. Each small school has its own curriculum and policies and teaching philosophy. Part of the politicization of this issue with the science labs appears to me to be some infighting among factions of faculty.

* Underperforming students do indeed appear to be under-served. One goal of redirecting funds here is to be able to afford to ensure that every single student at BHS has an academic advisor who monitors their performance and helps them become good students. Currently, students can coast through, achieving little, without anyone paying much attention.

* Money doesn't grow on trees. The opponents of this plan haven't suggested where else to find budget besides cutting the extra period science labs. BHS' per-student funding level is higher than state average but so are expenses around here - BHS ain't exactly flush, afaict.

* Its unclear any students will be harmed. One parent did tell me her struggling student benefited from these extra labs but I'm not so sure he would have benefited less given an academic adviser instead. Another parent complained to me that without the labs, it would be hard for his child to complete the requirements of several AP courses plus receive a "baccalaureate in international studies" which is offered by one of the small schools as a supplemental degree. (I found the latter parent's concerns understandable but hard to sympathize with.) Meanwhile, high achieving students can find plenty of opportunity at nearby University of California, several other colleges, Lawrence Berkeley Lab, etc.

* The principal might be an idiot in this matter. Several parents offered an argument against the plan that I thought was pretty good: The principal's proposal for how to spend the reclaimed budget is (as stated) too vague and lacks persuasive rationale. I won't be too surprised if not only does this plan go down in flames (labs not canceled after all) but, additionally, the guy loses his job. He pulled a few political parliamentary maneuvers to get the plan as far as he's gotten it and there is a lot of backlash now. (My take is that this is a shame because the impulse should be to refine and complete his plan rather than just lash out against it.)

* Opponents of the plan are playing pretty dirty with their rhetoric. One letter that went out to parents was saying (I paraphrase cynically here): "hey, you know global warming and swine flu? well, if we cancel these science labs there's nothing we can do about those things!"

* Metrics are not in sight. A comment by "riffer" in this thread offers the stereotypical "conservative" (I would say "common sense" in this case) complaint that teacher performance is off the table. It's even worse than that. The public debate around this issue utterly lacks any measured data about the performance of the courses slated for cancellation or the expected performance of the alternatives. In that sense, the entire question seems quite random - there's no good answer.