President Trump said last week that “we are all Americans. We all share the same home” and “the same heart.” He warned that “radical Democrats are trying to tear this country apart” with identity politics.

Left-wing activists are using the same divisive ideology to hijack our kids’ young minds. Across the country, leftists are demanding public schools teach “ethnic studies.” Many of these courses demonize America, label whites as oppressors and indoctrinate students to become “social justice organizers.”

California Democrats are pushing to make ethnic studies a high school graduation requirement statewide. Their draft curriculum defines ethnic studies as the “experiences of people of color in the United States” and the “forms of oppression” they’ve endured.

The California course urges students to become “agents of change” and mandates that all students complete an “engagement/action project.” Astoundingly, the course guide suggests only one project to meet this requirement: promoting “voting rights for undocumented immigrant residents” in local elections.

The curriculum tars white students — by dint of their whiteness — as oppressors. The course calls for “the privilege walk,” an exercise to teach white students about privileges they take for granted. “Whiteness” is defined as “more than a racial identity marker, it separates those that are privileged from those that are not.” White kids will have to endure this harassment to graduate.

Meanwhile, the course encourages minorities to think of themselves as oppressed. No mention of success stories like Supreme Court Justices Sonia Sotomayor and Clarence Thomas. No explanation for why millions around the globe of all races clamor to get into America.

The curriculum frames American capitalism as a system in which “people of color are disproportionately exploited.” Never mind that capitalism has lifted billions of people of color out of poverty.

Educators could point to billionaire real estate titan Jorge Perez, who built most of the Miami skyline, or former Citigroup and Time Warner CEO Richard Parsons as business role models for minority students. Instead the curriculum is one-sided, Marxian indoctrination.

To what end? To brainwash the next generation of voters into becoming leftist Democrats.

California’s curriculum, drafted by teachers and college professors, nearly slipped through without scrutiny, except that Jews in the state legislature noticed the curriculum condemned Islamophobia but not anti-Semitism. Parents and the public, who foot the bill for public schools, need to wake up and demand more control over what’s being taught.

Don’t leave curriculum reform to self-proclaimed professionals. The National Education Association, the largest teachers union, endorses reparations for slavery, Black Lives Matter and other divisive concepts. If parents want their children to learn the basics, without brainwashing, they need to win seats on local and statewide school boards.

The push for ethnic studies is a tidal wave, from Oregon to Indiana, to individual school districts like Bridgeport, Conn. Here in New York City, Schools Chancellor Richard Carranza prioritizes social justice ideology far above reading, writing and arithmetic.

What should students be taught? There’s no denying the horrible injustice of slavery, discrimination and other stains on America’s past. But teach American history objectively, the good and bad together, emphasizing how the nation’s founding ideals can help us overcome our shortcomings. Teaching kids they are victims won’t help them pass the Regents or succeed in life.

At its worst, ethnic studies also trashes the melting pot ideal, labeling American holidays and customs as Eurocentric and white. Such ideas, concocted by university professors, are now being served up to our kids.

Today all Americans who share a vision of opportunity, common values and color-blind justice need to recognize what’s happening in schools and stop it by taking control of school boards. The left’s push for ethnic studies — really, grievance studies — poses a serious threat to the America we hold dear.

Betsy McCaughey is a former lieutenant governor of New York.