(Bloomberg Opinion) -- Trust California to plunge deeper into the culture wars, even at the risk of undermining its own worthy objectives.

Under a bill headed for signature by Governor Gavin Newsom, the state would become the first to require that all high-school students pass an ethnic-studies course before graduating. The new mandate follows passage in August of a similar university-level requirement that is set to take effect in the 2021-2022 academic year.

As if on cue, President Donald Trump charged last week that U.S. schools are “indoctrinating children,” and vowed to bring back “patriotic education.” (My Bloomberg Opinion colleagues shared some thoughts this week on how that should go.)

California has the right idea. It’s past time for educators to confront long-standing gaps that have made it too easy for Americans to ignore the dark side of their own history. That’s been a recent goal of some journalists, scholars and the Black Lives Matter movement. Last year, a Pulitzer Prize-winning New York Times series sought to reframe U.S. history by arguing that “the start of this nation’s story” was not 1776 or 1787 but rather 1619, the year the first slaves arrived in Jamestown, Virginia. The series has since been integrated into history curricula nationwide. A year earlier, a book by the Harvard University historian Jill Lepore, "These Truths," won prizes for a nuanced look at America’s founding ideals and the extent to which the nation has lived up to them.

A small but growing number of states agree that schools need to bring a wider lens to U.S. history and integrate the perspectives and contributions of minorities, as well as the losses of indigenous communities. In addition to correcting the historical record, proponents argue that such courses also boost attendance and performance among students otherwise at risk of failing or dropping out.

But California’s unfunded mandate to create a separate ethnic-studies course is a flawed approach that risks draining money and attention from history and civics curricula. A better path is being blazed by Oregon, which aims to teach a broader narrative of U.S. history by deepening existing social studies and civics standards.

Under California’s high-school mandate, every district must offer ethnic-studies courses in the 2025-2026 school year, at a time when the state will probably be recovering from pandemic- and fire-induced financial devastation. Under state law, additional funding for the mandated course could take several years to approve. Even then, depending on the state’s fiscal health, the legislature could pay for it by draining some funding from other educational programs, according to Edgar Cabral, an analyst in California’s Legislative Analyst’s Office. (California is already anticipating future budget cuts; it took a decade to restore school funding following cuts made during the recession of 2008.)

California’s approach does offer districts some flexibility to modify existing courses rather than follow an ethnic-studies curriculum now being developed by the state that focuses on African Americans, Latinos, Asian Americans and Native Americans. However, for modified courses, ethnic studies must constitute the “primary content.”

By contrast, Oregon is establishing new statewide standards that broadly define what students should learn in existing courses rather than imposing new-course mandates. The revised Oregon standards, adopted in 2018, aim to “create teaching and learning opportunities for students to examine identity, race, ethnicity, community, religion, nationality and culture in the United States.” Thus, a discussion of the nation’s westward expansion and manifest destiny would include a focus not just on settlers, but also on the people who had lived in what is now Oregon since time immemorial, as well as the contributions of European and Asian immigrants.

Some states, including Vermont and Washington, where curriculum is set at the local level, also are focused on developing new ethnic-studies standards and course materials that local districts can choose to adopt, or not, as they see fit.

Making the courses optional, however, undermines a goal of public education: to create one culture out of many.

Ethnic studies have been controversial since they were first conceived in the 1960s. The Cornell University literature professor Noliwe Rooks has noted that the Ford Foundation backed early university Black-studies programs at least in part to keep students from being “lured into more radical politics like that of the Black Panther Party.” In the 1970s and 1980s, budgetary crises weakened funding for ethnic-studies programs.

In extreme cases — notably in Arizona — a backlash against ethnic studies at the high-school level provoked a ban, later reversed, on any public-school courses that “promote resentment toward a race or class of people, are designed primarily for pupils of one ethnic group, or advocate ethnic solidarity.”

Today, historians are pushing to correct distortions and omissions of America’s historical record. That’s a worthy goal for educators, but it could fail if it heightens social tensions. It’s also dangerous to drain funding and focus from civics instruction, which has declined over the last two decades as standardized testing regimens focused on math, science and English.

By contrast, developing standards that include a broader ethnic and racial perspective in American history and civics courses could serve to deepen education for everyone.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Andrea Gabor, a former editor at Business Week and U.S. News & World Report, is the Bloomberg chair of business journalism at Baruch College of the City University of New York and the author of "After the Education Wars: How Smart Schools Upend the Business of Reform."

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